How to change password to 4 digits
How can I change my password to unlock my phone back to a 4 digit password?
iPhone 6, iOS 12
This article walks you through what toUse a passcode with your iPhone, iPad, or iPod touch - Apple Support
Specifically step 3: Enter a six-digit passcode. Or tap Passcode Options to switch to a four-digit numeric code, a custom numeric code, or a custom alphanumeric code.
Is 4 digits not an option for you?
Do you have a school or work email set up on your phone?
~Lyssa