If your bags are due to a newly acquired water retention under eyes, you should treat the underlying cause, not have filler injected. The filler retains water too and will make it worse.
It it's aging/reduction of the fat pad below the eyes, you go to a plastic surgeon office so they fill in the hollow "tear trough" with hyaluronic acid filler. Do not go to "spas", "saloon", Mexico and NEVER have injected a permanent filler under the eyes, not even your own fat transfer. You will be deeply sorry if something goes wrong with a permanent filler, including your own fat transfer.