Having Errors In Creating New Permalinks Structure For My Site

Hi team,

So far the experience has been great with the Rankmath plugin and your support has been top-notch as well.
I am facing an issue with permalinks, and really need your help!

The current structure of my permalinks –

domain.com/(slug-of-post)

What I want,

domain.com/category/(slug-of-post)

I know it’s easier to set it up by going to settings and then adding categories as a custom permalink.

But the issue is, I have already a lot of posts published on my website, and when I try to update to the category/slug permalink structure, the previous links (original one- domain.con/slug), they are not working.

The previous ones are not getting automatically redirect to the new ones and all showing 404 posts not found.

There are plugins to redirect pages one by one, rank math also gives the option to do it one by one, but that will be too manual to do, I am in a need for a code or script, that will automatically redirect those links.

Hope you can help me soon.. really waiting for your reply!