@user01010, I'm working on getting an iOS device so I can take some screenshots, but in the meantime you can look at the screenshots above, and change these things:
Remove the "authorization" header
Add "token" under Request Body and paste your token from the Instructions page in as the value.
Remove the } and { characters.
Optional: change computername and triggername to computer and trigger.
Example:
computer=macbook
trigger=calculator
token=(token from the instructions page)