Despite the proliferation of password managers, Apple’s built-in Keychain does the deed, too. If you don’t mind wading through the world’s worst user interface. Chance Miller has a decent primer on iCloud Keychain for all your Apple kit.
The first thing you’ll want to do is make sure you’ve setup two-factor authentication. This makes iCloud Keychain much easier to use across all of your devices. Read our full how-to here on setting up two-factor authentication.
Once you’ve done that, on your Mac you’ll want to open the System Preferences app and go to the iCloud one. In that list, you should see “Keychain,” where you can tick the checkbox to enable it.
That gets your Keychain available on iPhone, iPad, and Mac. Simple enough, but the user interface could use, well, an interface worthy of humans, not techno-geeks and nerds.