Enable Telegram Translate Feature

Enable telegram translate on Android (Not working in the Telegram FOSS version):
Click the menu icon to the top left in the Telegram app (The 3 vertical bars icon)
Click settings -> Language -> enable "Show translate button" when you enable it It will default to "don't translate English"
now you should be able to tap messages that are not in English and translate them

For IOS (Iphones and Ipad's) follow this link:
https://tech.hindustantimes.com/how-to/how-to-translate-telegram-messages-in-your-language-71643467395834.html
Much the same was as on Android
From what I could gather from the Internet Telegram uses the buildin translate API in IOS which was introduced in version either IOS 14 or 15
IOS 15 seems to be supported on Iphones down till around IPhone 8 https://support.apple.com/en-gb/guide/iphone/iphe3fa5df43/ios