I can't really give you a script to fix, because I don't even know how to do it and I don't seem to locate it in the wiki. Any function, event.. anything? If so, please leave an answer or at least a link to the wiki post. I know this is possible as I've seen this done before in someone's Twitter.
It is already automatically done in studio, if you have the test purchase of one set up. It will prompt you to "Buy now" but not actually deduct any of your robux.