for supported devices, here are the official ways to download it: : You can join the official program via the Google Play Beta Page
This is the safest method, though you may not get the exact "3310" build number immediately, as beta slots fill up quickly. whatsapp beta 3310 download link
The number "3310" often appears in technical reports as part of a version string. Specifically, was a notable update that introduced features like sticker photos for status updates . for supported devices, here are the official ways