Send/receive custom UAVCAN messages

Hello everyone

I am trying to send a custom UAVCAN message using the CAN1 on Pixhawk v5x, I succeeded defining the message (the new custom message) in DSDL compiler in the source code and I can see that the source files were generated in the build file, honestly, I am still new with the DroneCAN, so, where is the part of the code that allow me to send or receive such custom messages. knowing that I read the documentation, it illustartes the use of a predefined modules for some sensors and actuators such as ESC, GPS, airdata…etc, I can not find anything about sending or receiving custom messages!!!
any help?!

Thanks in advance