How to change permalink with Redirect from old Link to new link

How to change permalink with Redirect from old Link to new link

My current custom permalink structure is /%postname%/

I wanna change to

/%category%/%postname%/ etc…

But I want user who enter by e.g my post name

https://aaaaaa.com/aaaa
will be redirect to

https://aaaaaa.com/category/aaaa

AND don’t want lose the search engine backlinks on the page.

Thanks for any help!