Open only access to the site through the PS and close the direct transition .htaccess?

Question

htaccess

How to close access to the site for direct visits, and leave only transitions from search engines.

Explanation:
If a person enters through any PS, and finds it in the search, he will be able to enter the site. In other cases, there will be an inscription, the site is not available.

Answer 1

You can catch the request on the backend side and look at the value of the http referer. And from this already build everything