I’m just confused by what you are asking. Are you asking if this community is OK with you self promoting D&D related stuff you made and want to sell? If it were up to me, I would say yes within reason, no one wants this community to become one loud ad. But I’m not sure the moderator would agree and it is up to them. I don’t see a no self-promotion rule yet but maybe message them directly?
If you just want to share content you found and generally participate like normal then I am absolutely sure you are wanted here.