Retrieve / Recover Data from an iPhone after losing Passcode or Device

If you have a backup either on iCloud or iTunes then you can get almost everything depending on when the backup was taken.

If you had turned on Messages in iCloud, iCloud Photos, Mail, Health data, call history under iCloud, and files you store in iCloud Drive your content is automatically stored in iCloud and is available on all devices that use the same Apple ID.

If nothing of the above is true then I am sorry to say you have lost the data along with the device.

If you enter the wrong passcode on your iPhone Lock Screen too many times, an alert lets you know that your iPhone is disabled. (Learn what to do if you see "[Device] unavailable" or "Security Lockout" on your iPhone or iPad.)

Lock Screen Passcode or Screen Time Passcode.

Following this process is the only way out if your iPhone is disabled. The steps given in this link will help you reset the passcode -> If you forgot the passcode for your iPhone, iPad, or iPod touch, or your ...

Note: If you have forgotten the Screen Time Passcode then restoring your device from a backup after the passcode reset will return the Passcode back to your device. So, please do not restore from a backup.