How can I assing a Project to a Project Category?

[Fernando Jimenez]

I don't see an option anywhere in Project Setting to categorize a project.

[Alexey Matveev]

Hello, 

It is a next-gen project. You can categorize it yet. If need to set a category for a project, you should create a classic project.

[Thomas Buchhorn]

I'm not really familiar with jira cloud.

From the docs, the option should be there to do this:

https://confluence.atlassian.com/adminjiracloud/adding-assigning-and-deleting-project-categories-844500732.html

Maybe you do not have any project categories yet?