Can the apple store upgrade RAM from 8gb to 16gb in a Mac Mini?

In this new model, the RAM is fully integrated into the M1chipset. There is no option to upgrade aside from completely replacing the chipset.

No. The RAM is a part of the M1 chip itself.

It depends on the model. Click here and look it up.

(186622)

Not for that model. It's the first entry listed.

(186624)