There's no automated, dashboard display to identify a fake Telegram account. All of them seem real enough.

But, there's a manual, slow way. You will need to send a private message to their accounts. If they respond, and their response to your query seems human enough, then that's a real account. There may be real accounts who choose not to respond, but certainly no fake account will pass this test.  Only, it's very time consuming; and some real accounts may choose not to respond, so false positives.