koel/app/Http/Requests/API/ObjectStorage/S3/PutSongRequest.php

<?php

namespace App\Http\Requests\API\ObjectStorage\S3;

use App\Http\Requests\API\ObjectStorage\S3\Request as BaseRequest;

class PutSongRequest extends BaseRequest
{
    public function rules()
    {
        return [
            'bucket' => 'required',
            'key' => 'required',
            'tags.duration' => 'required|numeric'
        ];
    }
}