I want this plane to fly to the blue cube. I want to be able to animate its flight in Unity or in external software. The problem is that I don't know exactly where this cube will be during the game. What are the best ways to do that? What functionality / assets / plugins to use?
Nothing yet XD. I am asking you to advise me for at least some ways to do that. I don't want to make it in a totaly wrong way and then redo this from the start.
You can calculate point, using math, chord (bowstring) of the circle. Assuming bow is none ballistic (part of the circle, not parabola). Otherwise, you need to look into ballistic equations.
Maybe there is. But I use that in my project. You can search of course for other solutions. Look in asset store for example, or/and forum, or/and web.