holy crap
wow I have never seen anything like that before, at least not that big. It appears the skin has come away from the muscle and is either filling with air or fluid. They could be cysts (fluid filled sacks).
If you've only had the fish a couple of weeks you might want to take it back to the shop. If it has been longer than that you have a couple of choices. You could try to puncture them and get the air/ fluid out. You could leave them and I guess they will continue to get bigger. Or you can put the fish down.
I would probably try poking a tiny hole in the small bubble and see what comes out. Then see if it clears that one up. Often once you remove the fluid, the skin can heal up and the problem usually clears up.
It could also be a genetic defect and that particular fish will always have the problem. In which case you might be better off euthanasing it.
The other option, which I have never tried but was recently brought to my attention, is to tie a thin piece of string around the sack near the mouth. The string is tightened up an over time cuts off the blood supply to the sack and it withers away before falling off. I’m not sure how well it will work on a fish and it might be easier to simply sedate the fish and puncture the sack.