Installing the Authy iOS app on a Apple Silicon Mac (M1/M2/M3/…) used to be the way to keep using Authy in the Mac Desktop, as early this year Authy announced their desktop applications would shut down by August (links further below).
I missed the September 2024 post [Wayback/Archive] Tell HN: Twilio quietly removes Authy iOS app from Mac App Store, stops updates | Hacker News, which basically means that if you had it installed on a Mac, it will keep being installed but never updated.
This was done silently by Authy owner Twilio making new installs are possible, never updating old installs any more thereby effectively decreasing your security.
Anyway: if you want to try side-loading, this is the iOS app link: [Wayback/Archive] Twilio Authy on the App Store.
Sideloadly (links further below) might work, but in reality it likely is better to have your MFA running on a separate device.
The Wiert Corner - irregular stream of stuff 