Today my child bought roblox on accident I want refund he didnt know bought on my account that was 20 dollers can you refund money pls thank you.

Here's how to request an app or media refund from Apple (From: Request a refund for apps or content that you bought from Apple - Apple Support - see the article for more detail.)

1. Sign in to https://reportaproblem.apple.com

2. Tap or click "I'd like to," then choose "Request a refund."

3. Choose the reason why you want a refund, then choose Next.

4. Choose the app, subscription, or other item, then choose Submit.

If you were charged for a subscription that you no longer want, you can also cancel the subscription using the directions in this article --> If you want to cancel a subscription from Apple - Apple Support

If you are having problems with unauthorized purchases being made on your device you may wish to always require a password for App Store and iTunes purchases.

Click here ➔ Require a password for App Store and iTunes purchases - Apple Support

"You can use Screen Time to prevent unintentional or unauthorized purchases from the App Store and other Apple services. You can require a password for purchases, prevent certain types of purchases, or disable purchasing completely." - Prevent in-app purchases from the App Store - Apple Support See how to 'Use Screen Time on an iPhone, iPad, or iPod touch' by clicking here --> Use Screen Time on your iPhone, iPad, or iPod touch - Apple Support

All you can do is to attempt a refund using the related article link you viewed at the top of the page. It is not guaranteed you will get a refund. Your child should not have your Password/Passcode as giving them this personal information is authorizing them for the use and that included purchases.

If your child has their own device, they need to have their own Apple ID and should be set up on a Family Sharing plan that is set with the "Ask to Buy" option. This puts the purchasing decision on you to allow them or not. If this is not set, then you are allowing them to make any purchase they want.

If the child was using your device, you can set up Screen Time settings to prevent purchases when they are using your device. Screen Time can be set with a PIN number and you can shut it off when you are using your iPhone and turn it on when the child is using it.