Sign in to App Store Connect
Open My Apps
Select the app you want to remove
Go to Pricing and Availability
Remove the app from sale
Save the changes
If needed, submit an app removal request through Apple Developer Support
Delete the app from sale in all selected storefronts
If the app is already approved and live, contact Apple Support to request complete removal
If you want to remove the app from your developer account, delete the app record only if Apple allows it for that app status