iPhone restore asks for a six digit passcode I never created

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 ...

moralesR wrote:

a 6 digit passcode that I never created.

Smart Phones neither have the intelligence nor has the hostility. Hence we need to look at our device settings and the way we synchronise our smart phones with Mac/PC/iCloud and also how careful are we in sharing our sensitive and valuable information with friends and family members.

Be careful when sharing the device's sensitive and valuable information with friends and family members.

Thumb Rules:

1. Please keep the screen lcoked when not in use. Access features from the iPhone Lock Screen - Apple Support
2. Enable  Guided Access before handing over an iPhone to kids
3. Don't share Apple IDs
4. Don't Jailbreak
5. Don't share sensitive information pertaining to your device and payment methods
6. Is this your corporate iPhone? Do you have any profile installed by your corporate / organisation / enterprise / School Management? Then please contact the system administrator of your corporate / organisation / enterprise / School Management. If you have installed it on your own --> Install or remove configuration profiles on iPhone - Apple ...