Alarm.com “Integration” means different things to different people. Most people only use the integration to arm or disarm based on a smartthings event, most commonly presence being detected as home or away. But that doesn’t mean that you have full control of all of the lights and other devices that a part of your alarm.com system, or that those devices will show up in your SmartThings app.
There have been a couple of different attempts at Fuller integration over the years, but quite a few of them have worked for a while and then stopped working as alarm.com made changes. There is no official integration.