All server plugins are executed directly in the Pandora FMS server as configured in the Servers -> Plugins section. Therefore the most detailed way to perform this test is to launch directly the complete execution with all its parameters from the Pandora FMS server shell, executing with the same user that is running the Pandora FMS server (by default root).
Once executed, the result of it has to be a data, that can be of numeric or alphanumeric type and it should match with the type of data that we have configured in the module creation. If it does not match, this will be the reason for not initializing it, unless we have configured the type as incremental, in which case it will show the output as it is.
It is important that the output does not show errors and the errorlevel of the execution is 0, because otherwise the server will obtain the output as an error and will not obtain values.