Regex OR results in two separate groups, how do I make capture it as a single group?

Question

I'm trying to capture the username for the following input string in GoLang regex, I expected anonymous and prettygurl91 to be in a single group, but it wasn't the case for the following pattern.

Input:

[Twitter] An anonymous user has posted a photo on 03-24-2024!
[Twitter] User prettygurl91 has posted a video on 03-25-2024!

Pattern:

^\[Twitter\] (?:User (.*?)|An (anonymous) user) has posted a (.*) on (.*)\!

Resulting groups:

Resulting group for [Twitter] An anonymous user has posted a photo on 03-24-2024!

1. Nil
2. anonymous
3. photo
4. 03-24-2024

Resulting group for [Twitter] User prettygurl91 has posted a video on 03-25-2024!

1. prettygurl91
2. Nil
3. video
4. 03-25-2024

What is was expecting was the following input strings to be grouped like so

1. prettygurl91 / anonymous
2. photo / video
3. 03-24-2024 / 03-25-2024

Answer 1

Solved with the following regex pattern

^\[Twitter\] (?:User|An) (.\S*).* has posted a (.*) on (.*)\!

Answer 2

You have multiple capture groups enabled which don't seem to serve any purpose. And the one capture group you want to use has been turned off. Try this version:

^\[Twitter\] (User \w+|An Anonymous user) has posted a .* on .*!