UE4 source from github with linked account?

I would like to download the source for UE4 from github. I have linked my github account to epic, but I keep getting 404. How can this be solved?
Ppl have written that a notification with an invite from epic should come in github, but I have not received any such.

Same here.
I even sign in 2 EPIC/Github account and it just not works.
I never received an invitation whatever I relink my account how many times