No. The Screen Time passcode is usually an independent passcode that's different from your iPhone unlock passcode. Screen Time passcodes are often used to manage and control access time limits to specific features on your device, such as app usage time, website restrictions, etc. While the iPhone passcode unlocks your device and grants access to data and settings. You can choose to set your Screen Time passcode to be the same as your iPhone passcode, or you can choose to set a different passcode. However, it is recommended to set a different one to increase device security.