Custom locations need to be added into your event before you start adding in transfers, as they need to be available to be used. Custom locations could be that such as a hotel, or the venue for example (any drop off or pickup location that is not a airport location).
To add custom locations to your event:
Navigate to: Event Setup > Travel > Transfers
Click on the “Locations” Tab
Click “Add Location”
Name: Give the location a name as the person registering will see it
Directions: Not necessary, but if you wish to give directions where to find the pickup at the location you can do so here.