I would normally post this question in the NetTalk Central forums, but they are offline right now.
Adobe has discontinued PhoneGap Build and ended investment in PhoneGap and Apache Cordova.
This website is no longer being updated.
and by following another link:
The PhoneGap Build service will be discontinued on October 1, 2020.
I guess I’ll be making a Progressive Web App. Or is there some other preferred way of creating Android apps using NetTalk? Fortunately my client is only using Android phones, so I don’t have the complication of having to support iPhones as well.