What Kristin said (there are some games listed as "text only" or "chat based"). One that I've seen come up on Roll20 is under Basic D&D or Other Games and they use Basic Fantasy RPG. Of course your best option is to look in LFG for games where the GM has announced text-only in the description like that, but there may be other options around too. There are sometimes games where the GM is the only person talking, and the players type their actions. There are sometimes games where many players use voice but the GM accommodates an individual player to use chat-only by your request. You can write it in your Player Profile bio, just as you explained it in the Original Post above. You can ask your same question in any Looking For Game listing, or include your explanation in your application, if the GM didn't say in the game description.