Open the chat with [[https://t.me/botfather | @BotFather]], the bot for creating other bots. Create a new bot there. You will need the bot username and token later. You can set the bot's userpic. It would be great if it matches your wiki's logo.
After creating the bot, send the `/setdomain` command and then send your wiki's domain.
You do not need to actually //host// the bot. It is enough for it just to be created in BotFather. You can also reuse a previously existing bot.
On login and register pages there is a blue button. If a user clicks it, they are prompted to give the authorization permission to your bot. The user's @username will be used as wiki username. Telegram users are part of the //editor// user group by default. Telegram users can use the wiki just like everyone else.