Change URL /Permalink for posts

Hi all,
At the moment I have:

Main page:
https://example.com/main/
Category pages
https://example.com/main/category/category-name/
Post pages:https://example.com/main/%postname%/

On my permalinks I have: /%postname%/

What I want for new posts is this:
Post pages:https://example.com/main/category/category-name/%postname%/

Well what I really want is this but I don’t think that is allowed from what I read in the docs:
https://example.com/category-name/%postname%/

Thank-you!!