Once you’ve earned 3,000 Competitive Points, you can unlock the Golden Gun of your choice — but choose carefully, as you’ll have to earn all of the points again to unlock another gold skin.
If you’re still struggling to unlock Competitive Play to earn your Competitive Points, we have an entire guide on how to unlock it, whether you’re a new player or struggling with the transition from Overwatch to Overwatch 2.
Source: https://www.distractify.com/p/how-to-get-golden-guns-in-overwatch-2