Pull Request for Issue # .
Creating (POST) and editing messages (PATCH) does not work
See https://docs.joomla.org/J4.x:Joomla_Core_APIs - Section Messages, creating and editing messages

Summary of Changes

messages.xml - add message_id to form so it can be passed as valid data
MessageModel - set the message_id key to the input
MessageModel - enable actions on sent and received messages

Testing Instructions

• Test sending and receiving Message to other administrators in the backend

• Do your own API calls on Message creating and editing

• or use my Postman collection https://github.com/MacJoom/j4x-api-collection Section 7.1

Actual result BEFORE applying this Pull Request

Backend: works

API: Creating and editing messages fails

Expected result AFTER applying this Pull Request

Backend: works

API: Creating and editing messages works

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• [ x] No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• [ x] No documentation changes for manual.joomla.org needed