If you’re having trouble accessing the Halo Infinite flight these steps may or may not help. Give it a go!
PC - Go to your profile, then scroll down to [My Flights] there may be a steam key for July, just enter into steam and you should get it.
XBOX - Go to the store, search for Xbox Insider Hub,
download it, open it up, then go to previews, find Halo infinite insider, next press show in Microsoft store, then download it. Done!
Hope this helps!
Its worth a shot!