send sms for OTP to verify phone number using Django and Plivo

I have web app build on Django. In the registeration process I want to make sure the user enter a valid phone number that he or she own it. Thus, I want to send OTP to the entered phone number using Plivo. The most service provider I found for Django is Twilio. However, in my country the Twilio price is as three times as that on Plivo. This is the reason why I want to use Plivo.

There is some explanation on the Plivo website, but it was not for verifing the phone number.
I do not want to send any ads sms or any other kinds of sms. it is just for registeration and when user wants to change the phone number.