Control + alt + A to open the "search actions" feature
Type "file watcher"
Click on the + symbol and select custom
Complete with
Name: Pint
File type: PHP
Scope: Project Files
Program: $ProjectFileDir$\vendor\bin\pint
Arguments: $FileRelativePath$
Output paths to refresh: $FileRelativePath$
Working directory: $ProjectFileDir$
Expand the "advanced options"
Uncheck: Auto-save edited files to trigger the watcher
Check: Trigger the watcher on external changes.
Click on Save.
Control + alt + O to open the "search actions" feature
Type "Actions on Save"
Check "Reformat code" BUT click on the file type list and uncheck PHP
Click on save.