If you can't remember a restrictions passcode that you set on a previous version of iOS, or you forgot your Screen Time passcode, you need to erase your device, then set it up as a new device to remove the passcode.
Solution 1: Remove the forgotten Restriction passcode by erasing your iPhone or iPad
If you can’t remember your passcode, you'll need to erase your device, which deletes all of your data and settings, including the passcode. We've found some reliable way of removing your forgotten restrictions passcode that is to erase your device via iCloud and Find My iPhone | iPad. See: ''How to reset iPhone without passcode''
Solution 2: Remove the forgotten screen passcode by restoring iPhone or iPad with iTunes
You can reset the screen time passcode on your iPhone or iPad with iTunes, it makes it easier to reset the iOS 13 screen time passcode. What’s more, this will also reset the iPhone to a factory reset. Before you start, make sure to turn off Find My iPhone or iPad.
Follow the steps below to remove your passcode:
Step 1: Open iTunes on your Windows or macOS PC. If you use macOS Catalina, open the Finder from the dock.
Step 2: Connect your iPhone or iPad to your computer and unlock the iPhone, then confirm this connection.
Step 3: Click "Restore iPhone" in iTunes or Finder. This will download and flash the latest iOS | iPadOS firmware to your device. A pop-up window will appear asking if you want to back up your settings before restoring. Be sure to click Back Up.
Step 4: After the firmware update is completed, you will be asked to set up as a new iPhone or restore the device from a backup. Select to set as a new iPhone.
Step 5: After the setup process is complete, you can now reset the screen time passcode.
If you cannot turn off Find My iPhone | iPad because you have forgotten your Apple ID password, Recovery Mode is the most common way to restore your iPhone to factory settings.
Solution 3: Remove the forgotten screen passcode in iOS 12 without data lose
With iSumsoft iPhone Passcode Refixer, you can also remove Screen Time passcode from iPhone or iPad ( iOS 12 ) safely without data loss. If you've lost or forgotten the Screen Passcode to your iPhone or iPad, this is the easy way to remove and turn off Screen Time passcode. More details, see: https://youtu.be/LpeMm9M7WVs