Citra won't let me join newly created channels

citra does not let me join the room that my friend has created and when he wants to join my room it gives him the same error message

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

As the error states, hosting a multiplayer room requires that you forward the port that Citra uses in your router settings. Citra does not host your rooms for you on our servers, the host’s computer serves as their server. This is why port forwarding is required for other users to be able to join your room. The port forwarding process is different depending on your router model, so we advice users to check their router’s instructions manual.