Step : 1 Create app/helpers.php file

First, create one helper class file in app/helpers.php path and in this file we are write our any custom helper logic into the function.

Step : 2 Add app/helpers.php file in composer.json file

Now, we are add our app/helpers.php file in composer.json file for a autoload section.

"autoload": {
    "classmap": [

         ...

     ],

    "psr-4": {

         "App\\": "app/"

    },

    "files": [

         "app/helpers.php" //Add This Line

    ]
},

After done this then once we are run following command.

composer dump-autoload