I am not sure. But when Ubuntu was building it’s mobile OS, it was putting a lot of emphasis on using GoQML. Even Shipping QT Creator with a Go plugin in its Dev tools. But the package used in this tutorial seems to be abandoned. With any personal Go and QT projects I use https://github.com/therecipe/qt now. As for being able to sell the software created with this I would assume it would require a license from QT itself. I looked into Obtaining a license a few years ago before they changed their license payment structure, and I don’t believe there was an issue with using Qt statically with a proper paid license.