Apple has discontinued its original method of notarizing applications, using altool, and, as of late 2023, requires developers to use notarytool instead.
To automate the complex command syntax required by notarytool, you can use the superb SD Notary 2 app or, for something smaller and less useful, this NotarizeApp AppleScript app. I created this app when SD Notary 2 had not yet been released, and you almost certainly do not need it, because SD Notary 2 gets the job done more elegantly and has far more options for customizing the process.
The app has "Distrib" in its name in order to remind me (and you) that it needs to be edited by individual users before being used. Feel free to rename it or leave it with its current name.
To use the app, first open it Script Editor or Script Debugger and very carefully read and follow the instructions at the top of the script. You will need to enter a few commands in a macOS terminal; one of them is a command that creates a profile that identifies yourself to Apple when uploading an app for notarizing. The instructions at the top of the script are all you will need. A lengthier explanation (which I relied on when writing the app) may be found here.
I used another copy of the app (with my profiile information included) to notarize this copy of the app.
For reasons that I don't understand, the app sometimes - not often - fails to notarize an app that I can successfully notarize with SD Notary. Most of the time, however, it works perfectly.
Edward Mendelson (edward [dot] mendelson [at] columbia [dot] edu).