Nextcloud Talk Commands - can't install the script

Is there any documentation of needed code so that files/scripts are accepted for import as talk commands?
I gave that a try an wrote some simple test scripts (all in php), but implementation always fails giving two issues:

  • The current PHP memory limit is below the recommended value of 512MB.
  • The script is invalid

This happens also when I try to install the sample commands. Or does it generally fail because of the php memory limit?

Nobody here who has a hint what to do to solve the problem or what the problem might be???