1.) Run php -i and paste it on xdebug online wizard.
2.) You will need to install install autoconf
3.) You will need to run the phpize on using the MAMP phpize not the default phpize that comes with the mac.
4.) Run configurer like this ./configure --with-php-config=/Applications/MAMP/bin/php/php7.2.14/bin/php-config

You might want to add these, incase if you are using PHPStorm.

xdebug.remote_connect_back=0
xdebug.idekey="PHPSTORM"
xdebug.remote_log="/var/tmp/remote_log"

Then follow the instructions as on wizard. and VOILAH !