Changing Permalink Structure

here are the terms to remember.
Default: "Ugly" http://example.com/?p=2
PATHINFO: "Almost Pretty"
http://example.com/index.php/yyyy/mm/dd/post-name/
mod_rewrite: "Pretty Permalinks" http://example.com/yyyy/mm/dd/post-name/

to use a structure without the date, you have to choose custom size.
Permalink https://ww.wp.xz.cn/support/article/using-permalinks/
Ningx https://nginxlibrary.com/wordpress-permalinks/

the old path is not forwarded to the new one, you have to use a plugin for this.

Note: you cannot use a new route for many date paths or otherwise you will be penalized for the seo, you can an old route in a new one instead.

I updated the topic, I wrote you something important.