I don't play in VR mode so I don't know the answer but I may have some information that will help. When I started playing HS2 on a laptop I didn't use a mouse, just the tracking pad. So I too had a problem starting the "action".
I found I could do the equivalent using two fingers back and forth on the tracking pad. It didn't work as well as a mouse which I have since bought but did work.
I'm sharing this in case it helps as I susepct in VR mode there may be some equivalent.
EDIT:
There is a whole help section in the manual on VR including using Occulus Quest
file:///D:/STNHS2DX11/manual_v/manual_en.html#ope
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