How to Integrate ERPnext with Door System in GYM?

Hi ERPnext Developers,

I customize the ERPnext for full GYM Management, and complete work,
I use the Customer Doctype in ERPnext as GYM Member,

Ever Member has Expire Date of Subscription, and We have Automatically Open Door, is Open by Member Card, (Old System Not ERPnext),
But now we want to Use and Integrate ERPnext with those door, how we can do this ?

Well in order to achieve this you will need to do some sort of integration between the door system and ERPNext which means some custom scripting will be required.

Yes, I know how to use server script, but I can’t find those integration between the door and ERPnext