Need more info. Hiking...??? With another pack or not?
I have a normal old fannypack. Red and black, asked for it for Christmas 10+ years ago to replace another I had modified, but worn out.
This one has two compartments, front and back. Both just zippered yes, but two compartments, which is important. I put the gun in the back so I can use the pack for other stuff. Above suspicion then, as I am the guy at the gym etc with my wallet, keys, snacks, mask, etc in the fannypack. So the items suggested above are good and comfy but can be a bit obvious; not necessarily "gun!" obvious but not normal so may stick out.
Critically, the gun does not just get tossed into the pack! It is in it's own holder. In the past I have made them myself, but mostly and now I just have a holster that I do not like much (today's is a crossbreed) that is either the same size as the compartment or is secured somehow to the fannypack body so it doesn't move around, and the gun doesn't wear on things. Also in that compartment, secured to/with the holster, a spare mag, a flashlight, and a small TQ.