How to export .3ds with animation.

I am trying to export a .3ds file and I can’t add animation to it.
I have made a walking animation I want to export to Blitz3D(It only supports .3ds and .x(Unsupported since 2009 in Blender) file formats).
When I export the character, I have the model but it doesn’t have the animation.
Is the problem in that I don’t have a skeleton for the character because it doesn’t even need one(It is a literal collection of a few cubes of different sizes and a sphere as a head).
Is it even possible to do that in Blender or I need to install 3ds Max for that?