This work for me try it
Go to app directory then to boot directory you will see production.php file.
That is:
app => Config => Boot => production.php
Change the ini_set('display_errors', '0') to ini_set('display_errors', '1').
Warning: When in production change back to initial ini_set('display_errors', '0')
Or
you can rename your file env in your project directory to .env after that open it and edit.
Search for # CI_ENVIRONMENT = production remove # and change production to development
Warning: When in production change back to initial CI_ENVIRONMENT = development to CI_ENVIRONMENT = production
For those experiencing intl error go to where your php installation directory edit the php.ini file remove semi-colon ";" from ;extension=intl to extension=intl. save the file and restart your server. I think this will solve that error. This particular editing of my php.ini was on php >= 7.3 so I haven’t check other version of php lesser than these versions which Codeigniter 4 does not support