Just did the Google thing on this. Its very limited. You have to be a nonprofit organization, school, or government entity to avoid the fees. It requires a special waiver.
Here is the relevant section of the documentation: https://help.apple.com/xcode/mac/current/#/dev88332a81e
It looks like it is only for XCode apps.
There are three ways:
ADP:
Apple Developer Program membership. Members of this paid program can distribute apps on the App Store.
Developer ID:
Apple Developer Program or Apple Developer Enterprise Program membership with a Developer ID signing certificate. Members with this certificate can distribute apps outside the App Store.
AD:
Apple Developer. Apple ID holders who have agreed to the Apple Developer Agreement to access certain resources on the Apple Developer website. No cost is associated with this agreement and developers cannot distribute apps.
As far as I can tell this is true. For now it doesn’t seems to be possible to ‘notarize’ apps made with other tools.
Also, sandboxing is mandatory which is mostly the reason why devs do not put their app on the AppStore.
If macOS10.15 only allows AppStore and Notarised apps to be run without a warning message (or not at all), Xojo devs are in big trouble. 
[quote=391309:@Christoph De Vocht]There are three ways:
ADP:
Apple Developer Program membership. Members of this paid program can distribute apps on the App Store.
Developer ID:
Apple Developer Program or Apple Developer Enterprise Program membership with a Developer ID signing certificate. Members with this certificate can distribute apps outside the App Store.
AD:
Apple Developer. Apple ID holders who have agreed to the Apple Developer Agreement to access certain resources on the Apple Developer website. No cost is associated with this agreement and developers cannot distribute apps.[/quote]
I know. I was replying to @Sascha S saying the developer program could be free for free applications. https://developer.apple.com/news/?id=01032018a&1515002682
[quote=391308:@Beatrix Willius]Here is the relevant section of the documentation: https://help.apple.com/xcode/mac/current/#/dev88332a81e
It looks like it is only for XCode apps.[/quote]
I see no reason for that to be true according to that link. Apple says signing needs to be done in Xcode too, but that isnt true either. Yes, Xcode will be required to do the uploading, but Apple doesnt care what language the app was written in, especially since Xcode is not uploading your code.
That’s the problem. Unfortunately I have found no way get your Xojo compiled app in the archieve list. That only happens when you compile it with Xcode.
Or do you know another way?
[quote=391316:@Christoph De Vocht]That’s the problem. Unfortunately I have found no way get your Xojo compiled app in the archieve list. That only happens when you compile it with Xcode.
Or do you know another way?[/quote]
I have not played with it yet. I’d probably compile an Xcode app first to see what kind of archive it produces. I’d expect there to be a command line app too, as most teams use an automated build process.
in the usa only.
It is a .pkg file which you can make with Appwrapper. But for some reason it is not recognised by the archive organizer.
OK, It is almost for certain you cannot get a non-Xcode compiled .app or .xcarchive into the Organiser.
There are two ways: compile it with Xcode or import it from an Xcode server bot (whatever that may be).
I am afraid it doesn’t look good for Xojo compiled apps.
Make a bug/feature request. There are other IDEs than XCode and Xojo.
[quote=391344:@Christoph De Vocht]OK, It is almost for certain you cannot get a non-Xcode compiled .app or .xcarchive into the Organiser.
There are two ways: compile it with Xcode or import it from an Xcode server bot (whatever that may be).
I am afraid it doesn’t look good for Xojo compiled apps.
[/quote]
Im not convinced yet. There are lots of ways to write apps, having this protection be limited to Apples languages doesnt make sense. Especially when the very feature is in response to malware making its way into legit software over the last year.
[quote=391344:@Christoph De Vocht]OK, It is almost for certain you cannot get a non-Xcode compiled .app or .xcarchive into the Organiser.
There are two ways: compile it with Xcode or import it from an Xcode server bot (whatever that may be).
I am afraid it doesn’t look good for Xojo compiled apps.
[/quote]
An .xcarchive is just a zipped folder. I haven’t tried yet, but I’m sure we can give Xcode whatever it needs to recognise the folder as a proper xcarchive. It’s probably an Info.plist or something at the top level.
You can make xcarchive in the Terminal using Xcode build but that only works with Xcode projects.
I tried to rename the .pkg to .xcarchive and it pops up in the Organiser. Sadly the upload button is disabled, no matter what you try.
Okay, I did a bug report in Bug Reporter:
The documentation at https://help.apple.com/xcode/mac/current/#/dev88332a81e describes how to get an app notarized for XCode projects. Some unfortunate souls use other IDEs to create apps. What is described in the documentation doesn’t seem to apply for those app. Either your documentation needs to be amended to show this works or you need to provide something that works for QT, Xojo etc.
@Beatrix:
Did you got an answer from Apple?
It really seems it can only be done with Xcode projects.
Nope. No reaction, yet.
They said in a talk you can do with command line tools, to just wait for those tools?
That’s already documented. You can do it with the commandline but only with Xcode projects.