Formula to calculate a position to fire at a target in a 3d space?,Formula to calculate a position to fire at a moving target in 3d?

i’v seen the post of the 2d formula, but i cant make it to work in a 3d space, any suggestions or solutions?
,i’ve seen the post for a 2d formula, but i dont really know what or how to modify it in order to work in a 3d space, any sugestions or solutions?

I don’t find any 2d formula. I only find 3d implementations which btw can be used for 2d as well.