I've been using pyrogram for a long time to automate stuff on Telegram. It also requires API keys to work. You basically just go the the official website, click a few buttons and it gives you the keys. You don't have to wait for approval.
The FOSS version on F-Droid is maintained by people unrelated to the official app as far as I understand. They got their own keys. There are other forks of telegram on F-Droid as well.
Using the API is really easy, it's not a problem. Though I agree that telegram is shit for other reasons.