How to send otp, message to a phone number from internet are discussed topics,
I can show you a partial so;ution for it.
It helps you to send sms to mobile number using internet.
Using way2sms api I created an small demo
Register in way2sms
Respond code 200 =Success
You need the login and password of way2sms.
Sms contains way2sms branding name.
Hope it helps.