Multiple armatures to single animation

Hi, when you have multiple armatures and each armature has it’s own animation, how can I put all animations into single animation?

For examle I can’t animate one and second armature together. If I then import this file into engine, it creates one skeleton (cuz all armatures are parented) but it does not do the same thing with animations. (it imports 4 animation files for each armature)

to start with it’s alway a bad practice to use multiple armatures if its controlling a single thing for the reasons your running into. You’ll have to combine your two armatures by selecting them both and hitting ctrl j, this wont harm your animations at all. I’m going to assume that you mean either either unity or unreal when you wrote engine. At this stage you can bring your rigged model in without any issue as both unreal and unity have ways of pointing to the animaitons you want BUT you can copy and paste your animations into a single action at this point if you want to