Sourcing a new battery from reliable venders

I'm looking into replacing the battery of my Garmin Fenix 6x Pro and would like to make sure I have a new battery with the same performance as the old, same mAh rating, brand name, and reliable. I'm happy to pay extra to make sure it's good, new, and safe. After all I'm strapping this to my wrist.

What I'm finding on obvious stores like Amazon and eBay so far isn't giving me confidence. How can I make sure I'm tracking down the right equipment and not cheap temu knockoff or used garbage?