If you use Laravel's built in integration testing, you can simply submit the form that posts to that controller method. That way you can check any redirects / success messages, too.
If you only want to test the repository method itself, you can write tests for the repository and just assert values exist in your persistence layer.
In that case, wouldn't you just want to test the repository method itself? Pass an array of values to the create() method and make your assertions against that.