Client Certificate for Telegram webhook

Hi!

There is setWebhook POST method in Telegram API. It is possible to specify an SSL certificate while setting a webhook url.
I wanted to allow requests to my domain only from telegram servers, so I came across Cloudflare API Shield. I generated certificate. Uploaded generated certificate’s public key to telegram servers. But I did not got it working properly. The certificate seems to be not working and I get the error: SSL error {error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed}".

Is it possible to use a client certificate the way I tried to? Should a cloudflare’s client certificate be trusted (its was not trusted when I tried to install public key on Windows)?