docker/docker/php/conf/xdebug.ini

[xdebug]
zend_extension=xdebug.so
xdebug.default_enable = 1
xdebug.remote_enable = 1
xdebug.idekey=PHPSTORM
xdebug.remote_autostart = 1
xdebug.remote_connect_back = 1
xdebug.remote_port = 9000
xdebug.max_nesting_level=400

; Uncomment this line if docker is running on Mac or Windows
; xdebug.remote_host = host.docker.internal

; OR uncomment this one if docker is on Unix, then replace the hostname
;    by the your current machine's name (type 'hostname' in a terminal)
xdebug.remote_host = dev