how to create helper in custom as in laravel code example

Example 1: add custom helper laravel

composer dump-autoload

Example 2: add custom helper laravel

"autoload": {
    "classmap": [
        "database/seeds",
        "database/factories"
    ],
    "psr-4": {
        "App\\": "app/"
    }
},
"autoload-dev": {
    "psr-4": {
        "Tests\\": "tests/"
    }
},