How do I send a text / sms message using php

I started poking around Twilio, I found a bit of sample code, but it appears in the sample code that there is an "includes" I cant find the php includes file. can someone that used this service guide me a little further.

which sample are you on

I agree. Twilio or CDyne SMS Notify are both excellent options.

As far as the includes goes, I'd suggest you follow the non-composer setup if you're not familiar with composer.

https://www.twilio.com/docs/sms/quickstart/php-manual-install

It will tell you where every file comes from.