NO.TLDR: you don't need OGL to make something "compatible with" DnD. Home brew and 3rd party adventure where always legal.
You just need it for using stuff like their logo, beholder, drizzt, or directly copying rules from the SRD, like quoting the fireball spell in a monster stat block.
Fixed.NO.
INCORRECT.
Bolded bit is NOT ALLOWED BY ANY SRD. Explicitly! Please can people stop repeating this canard? You've always needed a separate licence to do that. DM's Guild's licence allows that, but that means you lose 50% of the revenue of your product AND can't publish it anywhere but DM's Guild.
It's not showing as fixed for me, but ok.Fixed.
The main point is that you don't need permission, at all, to make homebrew and 3rd party adventures for 5e.It's not showing as fixed for me, but ok.