Setup xdebug 3.0 with PhpStorm
How to setup xdebug 3.0 with PhpStorm on macOS Big Sur
Assuming you have already installed PHP at 7.4, I am going to install xdebug.
pecl install --force xdebug
This will add [zend_extension="xdebug.so"] to your php.ini file. Just add a few more settings below that.