Trying to trade with myself

Trying to trade with myself, however it say the username is Invalid.
So Im trying to trade with myself in Pokemon US, however after I make the room and try join on a seperate citra file Its says my Username is invalid, anyone know how to fix this

In order for us to provide better support, we need to see the log generated by Citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File.

Make sure you’ve set up a seperate and valid nickname for both your Citra instances here:

Well you cannot have the same username in both the instances. So while connecting change the username in one of the instances.