Your Intercom Settings is mostly likely set to "Regular Phone Call" if you are just receiving a call from 240-709-1512. You can make this change yourself by going to your Profile page and clicking on Intercom Settings.
Click on the > error to change your Intercom Call Routing
Then select "Video call via Swiftlane mobile app" and click "SAVE" to save the settings.
You should now see you are setup for video calling and now you can unlock the door via the app.