Hi,
The multiotp uses Google authenticator for OTP purpose, if that what you are looking for I can provide server side implementation for the same.
In Google authenticator, you download their app on mobile and then enter a secret key which is unique for each user. After entering the key the app starts generating otp valid for 30 seconds. I can provide server side implementation for validation of this otp via implementing Google authenticator algorithm at server side and validation.
I can surely do that I have done that previously.
I work hard and provide quality code which you can see by my project ratings all 5/5
If you want something else, lets have a chat and discuss further.
Looking forward to work with you.