You should use engines with a price 'wall' or open source engines. Especially with the last, if the police of the main code changes, someone can took the source code of that engine and make a new version without a hypothetically bad politic.
But the problem is that my game started in 2019 (4 years!).
I was searching a bit and looks like you can port the code of a Unity game to Godot engine. I think that fits you, right?
Yeah, something like that:
