Telegram bot/content testing

I’ve just hired a dev to build a bot for Telegram, and I need to see how it functions on as many devices/platforms as possible. Equally important is seeing screencaps/videos how my content renders in different environments.

What’s the best method to test functionality and display using Telegram, similar to cross-browser testing for the web?

I’ve searched for app testing solutions, but it’s unclear how to test using a 3rd party platform like Telegram.

Thanks!