i cant remember my passcode on my phone and its locked how do i get it back to factory settings in ICloud

If your iPhone has iOS 15.2 or later installed, check out this link→How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support

Otherwise, see this Apple support link→If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Or watch this companion video ⬇️

How to reset your device

1. From your device's Lock Screen, try entering your passcode until your device asks you to try again later. When you're able to, repeat this step until you see the Erase [Device] option in the bottom corner of the screen.
2. 
3. Tap Erase [Device], then tap Erase [Device] again to confirm.
4. Enter your Apple ID password to sign out of your Apple ID on your device.
5. Tap Erase [Device] to permanently delete all of your data and settings.
6. When your device restarts, follow the onscreen instructions to set up your device again, restore your data and settings from a backup, and set a new passcode.

Source: How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support

If you can't reset your device

• Put your iPhone into recovery mode so you can erase it and set it up again.