@Arie_Laxed published a new version (v0.7.4) of his Virtual Devices app with a fix for the flow card Set a virtual sensor value so you can set the alarm_motion capability.
If you have a device that does not have the alarm_motion capability itself you can now use that device with Heimdall by using a Virtual Device and setting its value in a flow.
To do that you need to use the Set a virtual sensor value flow card form the Virtual Device and use it like this:
(enable motion)
(disable motion)
In order to use a Virtual Device like this it needs to be added with the Device Class Home Alarm or Sensor and at least the capability Motion needs to be selected.