There is no separate Mac app and no browser extension. The iPad app installs from the Mac App Store on M1 and later, and registers as a password provider.
Why this matters
There is no browser extension and no separate Mac app. The iPad app on Apple Silicon is the Mac version, and it registers as a password provider like any native one.
Steps
Install DroidPass from the Mac App Store, under iPhone & iPad Apps.
Open System Settings, then General, then AutoFill & Passwords.
Switch DroidPass on.
Open DroidPass once and unlock it so it has something to offer.
What happens next
Your logins appear in Safari and in other Mac apps the same way they do on the phone.
If it does not work
Open DroidPass and unlock your vault once. AutoFill has nothing to offer while the vault is locked.
Intel Macs cannot run iPad apps, so there is no Mac version for them.
Good to know
Requires an Apple Silicon Mac. Intel Macs cannot run iPad apps.
A locked vault offers nothing — unlock DroidPass once per session.