The openclaw doc page seems like it would be helpful.
https://docs.openclaw.ai/channels/telegram#telegramAssuming you can figure out how to get the token from BotFather on Telegram, the OpenClaw part I think would involve going into Config, clicking the “Raw” button to expose the openclaw.json file, editing the channel section so it reads just like the minimal config section in the OpenClaw docs. Then click save and click update.
The other way to edit the json file is to go into the OpenClaw shell through the Umbrel GUI, Settings -> Terminal -> OpenClaw Terminal. Brew install nano if you don’t have it. Then use nano to edit the file. Then go back to the GUI, right click OpenClaw, and restart it. Your Telegram settings should load.