If you go to your Game Details page, there is an 'Invite' button that
can be used to send game invites to people via email, and a link you can
share with others to bring them directly into your game. Be cautious,
however, where you post that link. You
have no control over who is clicking it, no way to prevent griefers
from filling your chat logs with nonsense and/or vandalizing whichever
map page the Player Ribbon is set to, and no way to tell who has been
drawing on your maps. If you do kick someone the join link changes and
requires you to edit your post with the new link. This is why we
strongly discourage posting open join links to places where people other
than your intended invitee(s) can see them. We encourage you to create a LFG listing , even if you do not enable that listing, and share the link to your listing. When someone posts to your LFG's Listing Discussion forum ,
in their post a big blue button will appear by their username and all a
GM has to is click 'Invite to Game' and an invitation will be sent
their way. Good luck, have fun, and welcome to Roll20! :)