Where are Friend Codes? (PC)

I have friends that want to join in, at least 4 of them
and I do not see a friend code, or anyway to get them in

So much for “Everyone gets to play halo infinite this weekend”
HAHAHA… but seriously, how does one get friend codes and where would they be?
I have another Steam Code for the last beta, but Idk if that is the one I used and it hasnt changed
Cause id just give it to my friend…

Im having the exact same issue… Did you ever find a solution?

Same deal, read an article on PC gamer saying current insiders would be sent a friend code. Buddy of mine played last weekend and wanted to invite me this weekend… No email. What gives.