How to rewrite files to files if it doesn't match on the index page?

Question

Apache HTTP Server

There are .php files, you need to make them available without extension. If the file is not found, the request is redirected to the main page to process requests related to the user's page.
On the site url like: example.com/login.php , example.com/username
2 questions.
- Is it correct that requests in case a user login is requested are redirected to the main page.
- How to remove the file extension