A similar question regarding a Home-Builder program system and how to get it connected is found here.
A system installed by a builder program company will be registered to an Alarm.com account through the installing dealer at the time of install. The panel can only be assigned to one Alarm.com account at a time.
In order to reuse the system with a different service provider, you will need to get that installing dealer to delete the Alarm.com account tied to it.
Often this is possible, some may give you trouble, it depends who you are talking to.
The installer code isn’t necessary to get started, nor would having it help out in this scenario. The Alarm.com account must be deleted for the panel to be reused.
All you would need to get started is the master user code, default 1234, which is your primary user code to arm and disarm.