How do I change the "master" password for Passwords app

Your iPhone's passcode / Face ID is considered the "master" password, as it should be. Once you authenticate to your iPhone, you have proven you are "you" and are entitled to unfettered access to everything else. Unless of course a particular app requires its own login credentials (which can and should use Touch ID / Face ID), but the Passwords app doesn't. You already authenticated by opening your iPhone.

Use the Passwords app to create, manage, and share passwords and passkeys across Apple devices - Apple Support

If the user forgets this password, it's not possible to open the app.

Nor would it be possible to use the iPhone. In that event, If you forgot your iPhone passcode or your iPhone is disabled - Apple Support describes what to do.

For Macs, If you forgot your Mac login password - Apple Support.

bobfromoneida wrote:

There does not appear to be any way to edit the password for the user to open the Passwords app. If the user forgets this password, it's not possible to open the app.

For example, I use 1Password, and make a routine of periodically modifying the master password to open that app. I see this as a basic, very important measure.

Apple's Password app does not offer this ability.

right. submit your Apple Feedback here: Product Feedback - Apple

associated to your admin/user psswd....

ref: How To Change Master Password

Understandable; I realize you posted in the Sequoia Community but my eyes are generally drawn to the profile information first.

... on an older system with no touch ID, it's possible for a user to have a blank login password. In that case, the Passwords app would not require a password for access and the treasure chest would be open? Ooops ...

Yes that is plausible. I know that it was possible to create a User Account with no password a long time ago, but I have tried and failed to create a User Account with no password on Macs for any recent macOS version. I have been unable to circumvent that requirement. Automatic login sure, but a completely blank / empty password... no.

I suspect that if one were to sequentially migrate a User Account — one created a long time ago, one with no password — to a newer macOS version, Migration Assistant would not object to that lack of a password. As time goes on and macOS programmers eventually become replaced though, it becomes increasingly likely a bug will arise that would manifest in some kind of unpredictable behaviour. Or, a security hole as you describe.

Passwords are considered "normal" and as time goes on it might be totally inconceivable one could have a User Account without one. As you say... oops.

What's worse is that Apple is already considering passwords obsolete in favor of biometrics and passkeys. Can't say I disagree with that.

I have the Passwords app always open on my laptop. I am unable to locate the P/W. Is there a way I can find the P/W in order to open the app on my MAC?

Forget my post. By reading inputs pertaining to my problem I tried something that I read and it worked. Thanks for reading my query and for the responses I received.