Start by checking out the possible solutions
on how to add SMS functionality to your website. Read the
Send SMS using HTTP:
With PHP you can easily submit SMS messages using HTTP
The Ozeki NG SMS Gateway can send incoming messages to your
PHP website through HTTP GET and POST requests:
SMS from MySQL:
If your website has a MySQL database, check out the
Checking if the SMS message has been sent
Has the message status changed?
You can check if the SMS has been successfully sent by checking
the table of outgoing messages. If the message status is "sent", the message
has been sent.
Receive SMS on a Website (PHP)