In a hybrid, as long as the car is powered up the 12V battery should be being charged just the same as if you were driving a normal car.
You don't have to drive anywhere, just sit in the car with it powered up for 30-60 minutes.
The petrol engine will start as necessary to keep the HV battery charged sufficiently, and the HV battery charges the 12V battery all the time the car is on.
If you turn off the climate control then the petrol engine won't start that much, or you can leave it on if it's cold outside and you want heat/are in an open area.
It's what I did with my Auris hybrid during the first lockdown, as they have very weak 12V batteries that cost a fortune to replace.