Password Managers and Applications Outside Browsers on a Mac

Is there a password manager out there that deals with applications on the Mac? I notice that the iCloud Keychain sometimes works with applications. Apparently it is up to the developer to enable it. This isn’t a problem on the iPhone or iPad where all the apps come from the App Store (and are presumably told to enable it).
Is there a common protocol that developers use to enable password managers (i.e. if iCloud Keychain is enabled are all password managers enabled?). Do any password managers work with apps that are not enabled?

I’m no expert and don’t own a Mac. However, from what I’m reading, it seems that iCloud Keychain is its own separate thing and there’s no real way for other password managers to use the same protocol.

There are some articles where people ask Apple to release an app that would give you access to your Keychain to allow you to add in extra stuff that wouldn’t be connected to a particular app (which might let you save a password and copy and paste it into an app that doesn’t support Keychain), but nothing seems to have been done in that regard.

Supposedly 1Password allows you to do something like I described above, but I have no idea how good it is as a password manager, since it isn’t integrated into the OS like Keychain.

There is an app on Mac. It’s called “Keychain Access”.

OP, there’s various password managers that integrate into your browser if that’s good enough for you. I use LastPass (free on desktop).

What, exactly, are you trying to do?
You mention OSX “Apps” - do you mean other browsers, or something like a CAD program?

Sorry I didn’t get back sooner, but yes, that is exactly what I am asking about. The app that inspired my question was Truefire (an app that provides guitar instruction). You need to log in to access content. For anything on the browser, the password manager works fine. I usually use Roboform but sometimes use Keychain. When I open the app, however, I need to open the password manager and copy and paste the password. It is not a huge deal, I was just wondering if there were an easier way. In contrast, when I deal with apps on my iPad Pro, most apps open with Face ID (obviously I do not have Face ID on my Mac but it would be nice to simply populate the password with the password manager).

Browsers have (somewhat) standardized login and password submission fields, so Safari and Keychain can auto-fill those fields, and third-party apps (like 1Password, which I use) can do so, too.
I’m not sure that’s true with non-browsers. 1Password has an extension (plugin) for browsers, I don’t think they have anything for random applications. If this app is the only one you have this issue with, you could probably automate it with a keyboard shortcut.