@Mrinal_Chakraborty
Actually no.
That’s because any WhatsApp API is paid as WhatsApp itself charges this service.
But the notification sending script itself can be coded and hosted for free in AWS and GCP.
I have a Python script that performs an integration with Twilio, and sends WhatsApp notifications through my WhatsApp business account. That script itself is free, but Twilio is not.
Be careful with solutions that offers free WhatsApp notifications API! it’s probably a scam, as it violates WhatsApp guidelines.