Hii,
You can create a constants.php page in config folder if does not exist. Now you can put constant variable with value here and can use with Config::get('constants.VaribleName');
Example
return [ 'ADMINEMAIL' => 'info@bestinterviewquestion.com', ];
Now we can display with
Config::get('constants.ADMINEMAIL');
Hope this is helpful!
Thank you!!