Why is the Overwatch 2 beta not showing up?

gamepur.com:

If you’re trying to get into the Overwatch 2 PvP beta, you might be encountering a few issues when attempting to launch the game. Multiple people are trying to jump into the game right now, and with this amount of people, it’s hard for the Battle.Net servers to keep up with everyone. However, if you received a Twitch drop or an email to access the game, the Overwatch 2 might now appear on your launcher. Why is the Overwatch 2 beta not showing up?

As previously said, it all comes down to the number of people trying to jump into the game simultaneously. The first Overwatch 2 PvP beta officially launched on April 26, and everyone who could get into the game was accepted through an email. Many people are watching verified Twitch steamers for four hours to receive their Overwatch 2 PvP beta invite. When that happens, not everyone immediately receives these invitations. Instead, the ones who received the drops will need to wait until all of the requests ahead of them can be put through, which could take some time.

You might expect to see your Overwatch 2 beta invitation arriving the day after it was confirmed on your Twitch account. However, if it’s been longer than a day or two, you may want to make sure you connected the correct Twitch and Battle.Net accounts to avoid logging into the incorrect one. Although, it’s likely because of the many users attempting to get into the game. With so many players trying to get in at the start of the PvP beta, it’s been causing errors, such as the unexpected server error notification.

We recommend giving it some time and double-checking you’re logging into the correct Battle.Net account.