Pass Code
How do you delete your pass code from your iPhone? It’s annoying….
If you know the passcode, go to Settings > Touch ID & Passcode (or Face ID & Passcode), enter the passcode, scroll down and tap "Turn Passcode Off." Be aware that you will no longer have Touch ID or Face ID -- they require that you have a passcode on the device.
If you don't know the current passcode, see: If you forgot your iPhone passcode - Apple Support