Expanding foam between plasterboard and concrete floor?

[GB8]

There is a gap at the bottom between the plasterboard wall and the floor in my garage which I believe is standard procedure.

I have used some cheap wood to cover the gap, should I take the wood off and fill the gap using expanding foam then put the wood back on to cover it?

Lots of bugs getting in and I would like to seal it up.

See picture attached.

 

[Bondo]

Ayuh,..... That's a water gap, so the drywall won't **** up moisture from the floor,.....

Fill it in, 'n you defeat the purpose,.....

Stoppin' the bugs, starts Outside the building,.....