forge/app/Http/Controllers/Api/V0/ApiController.php

<?php

namespace App\Http\Controllers\Api\V0;

use App\Http\Controllers\Controller;
use Illuminate\Support\Str;

class ApiController extends Controller
{
    /**
     * Determine if the given relationship should be included in the request. If more than one relationship is provided,
     * only one needs to be present in the request for this method to return true.
     */
    public static function shouldInclude(string|array $relationships): bool
    {
        $param = request()->get('include');

        if (! $param) {
            return false;
        }

        $includeValues = explode(',', Str::lower($param));

        if (is_array($relationships)) {
            foreach ($relationships as $relationship) {
                if (in_array(Str::lower($relationship), $includeValues)) {
                    return true;
                }
            }

            return false;
        }

        return in_array(Str::lower($relationships), $includeValues);
    }
}