Commands in the Actions page - MP

I am working on my project and have an on board payload, at the moment I am looking to have a basic serial connection, I want to know what the “Message” button on the action tab actually produces, as a mavlink packet. I would also like to know what the other buttons do, I have been searching and searching but cannot find this in documentation anywhere

They have Mouse Over descriptions

I am referring to the mavlink messages that can be used in cpp/python not a description

You asked what the Message Button does. This is what it does:

That would be the serial that would be sent to the vehicle, I am asking what the message name is ei. ‘HEARTBEAT’ - a larger list is on Messages (common) · MAVLink Developer Guide here but I do not know what message type is being sent