Hello Jhonson,
I always try to use the latest XCode version, the latest stable one, to be exactly: not the possible beta releases. In fact what I do is to download the latest release of XCode from this website: https://xcodereleases.com/, so, instead of install or update the installed XCode, what I do is to download the release from the referred file, then extract / unzip it, and finally execute the obtained "app" file.
Curiously I can see in the referred page a XCode 12.5 release. In your case I will try with this latest release, even when in my latest compilation I use the 12.4 release (XCode is updated very quickly sometimes). So that's what I do: instead to upgrade the installed XCode, what I do is to download the "xip" file from the referred page, then extract / unzip that file and then directly execute the "app" file, which is like "Xcode.app". Doing that I use always the very latest release, without need to update the installed version, which commonly requires more time.
So the answer is "use the latest stable release". Note that this may also requires a specific version of iOS (if you plain to run the app in a device attached in the Mac OS computer, in order to test the app if you needed). Commonly we no need to do this, because, if the app works as expected in the AB debugger, maybe also try it in an Android device (which is more easy to try than in a Mac OS / iOS device), we can assert 99% of the times that the app also works in a iOS device as expected.
Please, just post here if you have any trouble. Remember that I mention above that you can also search around the web for specific problem / error messages: this is honestly not to avoid to help you, sir, it's because some problems can be specifically related with your Mac OS / XCode version / Cordova version, etc., and, commonly we can find the proper solution by searching for the error message, for example, so you can get the right help more fast and quickly, but, of course, I am here if I can help in something.
Said that, I must recognize that unfortunately I am not very confident with the Mac OS / XCode environment, for example, in order to upload the IPAs to the store, or to get the IPAs using other ways like "Enterprise" or "Adhoc" modes (you can see all these possible ways when "Archive" the project from XCode), somethings are needed, like the right certificates, provisioning profiles, etc. I am not very confident with this part... because these certificates, provisioning profiles, etc., must be created using the Apple account, and this is something that my customers do for me.
But again, just post here in case you find any problem and I will try to help you as best as possible. What I can guarantee is that once we configure the environemtn in the proper way, that is, once XCode is ready, Cordova is ready, etc., run the apps in an attached device or get the IPA files ("Enterprise" or "Adhoc"), or upload the IPA to the Apple Store, all of these are quite simple once we have the environment ready. Not as easy as Windows / Android, because in this last case the things are more easy, but, I compile and get the IPA and publish to the store in Mac OS without too much troubles once the environment is ready and the possible problems are solved, for example, maybe a new version of XCode requires to download and install again the proper Command Line tools, etc.
P.S. Don't forget to use the very latest release of AB (updated just yesterday) since a new option is included in order to get the Cordova's configuration file with the right stuff to use the latest WKWebView for iOS, which is required by the Apple Store and recommended instead to use the old WebView. So update your AB copy in order to use the current release, and your Cordova's config file will be ready to use the latest WKWebView. Before this release we can add the right stuff using the Cordova -> Configuration -> Extra XML option, but, with the latest release we no need to use this option to add the right stuff to use the WKWebView webview: AB add the right stuff automatically for us.