Stop passcode requirement

I’m not sure that’s possible and cannot recommend doing it for security reasons, even if it were. You may find it easier to set up Face ID which will allow you to simply pick up the phone and look at it. Your face will open it without having to enter a passcode. Instructions are here:

Set up Face ID on iPhone - Apple Support

On my iPhone I can go into Settings, then to Touch ID& Passcode. Then go down a bit and there is an option to turn Passcode On or Off.