How to get public URL of uploaded image Laravel API

I am writing an API which is supposed to upload image and then return the url to access the image. Uploading is good but I am unable to access the image in url, can someone guide me how to access the image. Following is the code to upload the image.

public function uploadPicture(Request $request){
    $file = base64_decode($request['image']);
    $fileName = str_random(15).'.'.'png';
    Storage::disk('local')->put($fileName, $file);
    return $this->sendResponse(['url'=>asset('storage/'.$fileName)], 'Image is uploaded');   
}

the response of the above api is

{
    "success": true,
    "data": {
        "url": "http://localhost:8000/storage/BMqX7BC61XqjOhL.png"
    },
    "message": "Image is uploaded. "
}

The location is the image is project_root/storage/app but in browser is say the 404 not found

can someone guide me how to access image in browser? I am using Laravel 5.7

via Chebli Mohamed