htaccess for redirecting all requests to public folder in shared hosting

I'm afraid that's not a recommended practice. You should put the content of /public inside your /public_html (e.g.) and everything else one level up.
https://codeigniter4.github.io/userguide...tml#public

Thanks, it could be the nature of my particular hosting, one level up is not an option there.

You can see things I made with codeigniter here: itart.pro its not overly impressive as I have very little time to learn.