I will create python api using Django
now I trying to verify phone number using firebase authentication  end send SMS to user but I don't know how I will do
The phone number authentication in Firebase is only available from it's client-side SDKs, so the code that runs directly in your iOS, Android or Web app. It is not possible to trigger sending of the SMS message from the server.
So you can either find another service to send SMS messages, or to put the call to send the SMS message into the client-side code and then trigger that after it calls your Django API.
python api verified number usinf firebase