How to add Labels/ Assign people for Pull Requests?

[19valentin99]

I would like to ask how it is possible to add: Labels or to Assign people to check my pull request because, when I was submitting the pull request I couldn't see the buttons that usually appear on the examples that are on the internet and I can not modify them afterwards.
What I see is something like this:

Thank you.

[haipinglu]

You need the right to do so. I just gave it to you.

[19valentin99]

Thank You.

[haipinglu]

The template was not clear in this aspect. I will update.

[19valentin99]

Thank You.