Update: The official Zoom integration has been launched in v0.9.2.0. You do not have to use this workaround for Zoom.
Until official integration of third party web conferencing apps are launched, you can use this workaround to use them with WPCal.
- When selecting the Location, choose the Custom option.
- In the 'Enter a location of your choice' field enter "Zoom" or the name of any app that you will be using.
- Click on the [ + Add additional info ] link and in the field that appears, add the invitation link and hit Add Location. This will be shown to your invitees AFTER the meeting is scheduled.