How to implement OTP verification for mobile number registration?

[Namit]

Guys

I want to create a facility wherein it would be necessary for people to enter a mobile number when registering a shopify account.

Additionally the mobile number needs to be verified via OTP authentication. 

How do I do this. Please help

[aaditya1992]

Hi You can use any third app . and if you want that by custom coding , I can do it for You .

[nodnyl1966]

Hi, if you create custom coding for the otp verification, there would be no monthly payment? am I going to be billed for the SMS? how much is the custom coding?