EC21-E Telegram

I have an EC21-E, it is possible to send messages to a telegram bot.
I tried and tried again with HTTP (S), I get error 550
what can I do?

Dear Angelo,
Thanks for your inquiry in Quectel forum.
About your issue, it is better to provide your whole test AT log, then we can check what is the problem. And you can check the following document to confirm it. Thanks!
Quectel_LTE_Standard_HTTP(S)_Application_Note_V1.1.pdf (394.7 KB)