@developerbayman I hear you. I tried to register with four different clients, including the Ubuntu Snap and the Telegram webapp. All claimed to be sending a code to my 'other devices' or by SMS. Only way I actually got anywhere was to install the official Android SDK APK (from the Telegram website) to an actual Android device. (Going through the Google Play Store would probably have worked, but I would draw the line before that!) After registering with the official Android app, all the other clients authenticate no problems.