@cabat , you are right

I commented on the MY_PARENT_NODE_ID line and after uploading sketch, I still receive on the gateway.

The problem was elsewhere but I don't understand where

@cabat , The Gnd is not needed, only the A and B pins are needed, I think.

I tested a 2nd node with the same sketch, only the "MY_NODE_ID" was changed.
It works perfectly without needing the "MY_PARENT_NODE_ID" directive.

Both nodes are communicating well with the gateway now.