Finnaly I solved it!!! As I was getting errors since I started, I decided to install node, which broke my nodejs installation, I found the answer here.
I removed the package node and everything went perfect! Thank you so much!

@Russ Does not work, thank you anyways!

@Russ Thanks for answering, I can't reinstall raspbian again because I have other services like pihole, pivpn...
At the beginning I could execute triggercmdagent and asked me to enter the token, however as the apt upgrade still being saying that wasn't successful I reinstalled it, and since that didn't work.
This is my output using su

pi@raspberrypi:~ $ sudo su -
root@raspberrypi:~# apt remove triggercmdagent

Reading package lists... Done

Building dependency tree

Reading state information... Done

The following packages will be REMOVED:

triggercmdagent

0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.

1 not fully installed or removed.

After this operation, 0 B of additional disk space will be used.

Do you want to continue? [Y/n] y

(Reading database ... 51918 files and directories currently installed.)

Removing triggercmdagent (1.0.1) ...

root@raspberrypi:~# rm -rf /usr/share/triggercmdagent

root@raspberrypi:~# dpkg -i triggercmdagent_1.0.1_all.deb

Selecting previously unselected package triggercmdagent.

(Reading database ... 49379 files and directories currently installed.)

Preparing to unpack triggercmdagent_1.0.1_all.deb ...

Unpacking triggercmdagent (1.0.1) ...

Setting up triggercmdagent (1.0.1) ...

Directory 'node_modules' exists. Running 'npm rebuild'

dpkg: error processing package triggercmdagent (--install):

installed triggercmdagent package post-installation script subprocess returned error exit status 1

Errors were encountered while processing:

triggercmdagent

root@raspberrypi:~# triggercmdagent

root@raspberrypi:~# /usr/share/triggercmdagent/app/src/installdaemon.sh

cp: cannot create regular file '/root/.TRIGGERcmdData/triggercmdagent.service': No such file or directory

/usr/share/triggercmdagent/app/src/daemonmgr.sh: 10: /usr/share/triggercmdagent/ app/src/daemonmgr.sh: cannot create /root/.TRIGGERcmdData/triggercmdagent.servic e: Directory nonexistent

/usr/share/triggercmdagent/app/src/daemonmgr.sh: 11: /usr/share/triggercmdagent/ app/src/daemonmgr.sh: cannot create /root/.TRIGGERcmdData/triggercmdagent.servic e: Directory nonexistent

cp: cannot stat '/root/.TRIGGERcmdData/triggercmdagent.service': No such file or directory

Failed to start triggercmdagent.service: Unit triggercmdagent.service not found.

Failed to enable unit: Unit file triggercmdagent.service does not exist.

Unit triggercmdagent.service could not be found.

root@raspberrypi:~# apt-get -y install npm nodejs

Reading package lists... Done

Building dependency tree

Reading state information... Done

nodejs is already the newest version (10.19.0~dfsg1-1).

npm is already the newest version (5.8.0+ds6-4).

0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

1 not fully installed or removed.

After this operation, 0 B of additional disk space will be used.

Setting up triggercmdagent (1.0.1) ...

Directory 'node_modules' exists. Running 'npm rebuild'

dpkg: error processing package triggercmdagent (--configure):

installed triggercmdagent package post-installation script subprocess returned error exit status 1

Errors were encountered while processing:

triggercmdagent

E: Sub-process /usr/bin/dpkg returned an error code (1)

root@raspberrypi:~#

This is the output, thanks

sudo dpkg -i triggercmdagent_1.0.1_all.deb
(Reading database ... 51918 files and directories currently installed.)
Preparing to unpack triggercmdagent_1.0.1_all.deb ...
Unpacking triggercmdagent (1.0.1) over (1.0.1) ...
Setting up triggercmdagent (1.0.1) ...
Directory 'node_modules' exists. Running 'npm rebuild'
dpkg: error processing package triggercmdagent (--install):
installed triggercmdagent package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
triggercmdagent
pi@raspberrypi:~ $ cd /usr/share/triggercmdagent/app
pi@raspberrypi:/usr/share/triggercmdagent/app $ npm install
pi@raspberrypi:/usr/share/triggercmdagent/app $ cd ~
pi@raspberrypi:~ $ sudo dpkg -i triggercmdagent_1.0.1_all.deb
(Reading database ... 51918 files and directories currently installed.)
Preparing to unpack triggercmdagent_1.0.1_all.deb ...
Unpacking triggercmdagent (1.0.1) over (1.0.1) ...
Setting up triggercmdagent (1.0.1) ...
Directory 'node_modules' exists. Running 'npm rebuild'
dpkg: error processing package triggercmdagent (--install):
installed triggercmdagent package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
triggercmdagent
pi@raspberrypi:~ $ sudo systemctl stop triggercmdagent
Failed to stop triggercmdagent.service: Unit triggercmdagent.service not loaded.
pi@raspberrypi:~ $ sudo /usr/share/triggercmdagent/app/src/removedaemon.sh
Failed to stop triggercmdagent.service: Unit triggercmdagent.service not loaded.
pi@raspberrypi:~ $ sudo apt remove triggercmdagent
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
triggercmdagent
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
(Reading database ... 51918 files and directories currently installed.)
Removing triggercmdagent (1.0.1) ...
pi@raspberrypi:~ $ sudo dpkg -i triggercmdagent_1.0.1_all.deb
Selecting previously unselected package triggercmdagent.
(Reading database ... 49379 files and directories currently installed.)
Preparing to unpack triggercmdagent_1.0.1_all.deb ...
Unpacking triggercmdagent (1.0.1) ...
Setting up triggercmdagent (1.0.1) ...
Directory 'node_modules' exists. Running 'npm rebuild'
dpkg: error processing package triggercmdagent (--install):
installed triggercmdagent package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
triggercmdagent
pi@raspberrypi:~ $ triggercmdagent
pi@raspberrypi:~ $ sudo /usr/share/triggercmdagent/app/src/installdaemon.sh
cp: cannot create regular file '/root/.TRIGGERcmdData/triggercmdagent.service': No such file or directory
/usr/share/triggercmdagent/app/src/daemonmgr.sh: 10: /usr/share/triggercmdagent/ app/src/daemonmgr.sh: cannot create /root/.TRIGGERcmdData/triggercmdagent.servic e: Directory nonexistent
/usr/share/triggercmdagent/app/src/daemonmgr.sh: 11: /usr/share/triggercmdagent/ app/src/daemonmgr.sh: cannot create /root/.TRIGGERcmdData/triggercmdagent.servic e: Directory nonexistent
cp: cannot stat '/root/.TRIGGERcmdData/triggercmdagent.service': No such file or directory
Failed to start triggercmdagent.service: Unit triggercmdagent.service not found.
Failed to enable unit: Unit file triggercmdagent.service does not exist.
Unit triggercmdagent.service could not be found.
pi@raspberrypi:~ $

I get this errors while trying to install triggercmdagent in my raspberry pi zero (no wifi version, running with eth cable), I have installed everything you said in last posts, npm, nodejs... Everything. Tried rebooting, reinstalling npm, nodejs, triggedcmdagent... and everything gets to the same point.
Thanks.

pi@raspberrypi:~ $ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
Setting up triggercmdagent (1.0.1) ...
Directory 'node_modules' exists. Running 'npm rebuild'
dpkg: error processing package triggercmdagent (--configure):
installed triggercmdagent package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
triggercmdagent
E: Sub-process /usr/bin/dpkg returned an error code (1)