i got an xbox messege sayiing this

hi i got an offiical xbox text saying im allowed to joined so i tried to like i did the other times but the app wont let me join!? HELP!!!

You don’t mention what it is you’re allowed to join. I’m going to assume you mean you’ve been invited to participate in the Network co-op flight. If so, have a look here:

https://insidersupport.halowaypoint.com/hc/en-us/articles/7623367397268-Network-Co-Op-Flight-Xbox-Installation-Instructions