How do I access saved passwords on a macOS Catalina 10.15.17 desktop?

Though there are some other paths, here is the app to use: Applications > Utilities > Keychain Access

macOS 15 and later use the Passwords app:

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

(One potential source of confusion that can arise here: macOS 15 is well after macOS 10.15; five versions later.)

ggkids wrote:

Is there always a charge for password managers?

The Apple password manager is free.

Third-party password managers will generally cost to acquire, or will require subscription, or both, yes.

Apple Keychain and (when enabled) iCloud Keychain is integrated across the Apple platforms and with iCloud, and is integrated within Apple apps including Safari, and integrated within many third-party apps, and is free.

iCloud Keychain (when enabled) syncs passwords across all devices associated with the same Apple Account.

More current versions have an improved UI, and can import and export passwords to allow easier transitions among password managers. Also available are password-sharing functions.

Set up iCloud Keychain - Apple Support

Older macOS versions can also use Safari:

Find saved passwords and passkeys on your Mac - Apple Support

Here is the newer Apple password managers user interface:

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