Thanks for the detailed answer, stikkanimate!!
I knew there is a simple solution!

Hi guys!
A small question about how to hide an IK target.
I have one skeleton. I made 2 animations in different projects. The first animation (idle) was made using IK targets on feet, and run animation was made without these IK targets. Now I want both animations to be in the same project, but the ik-target ... Is there any way to use both animations as they are, without remaking any of them? So that, for example, the ik-target is not involved in the run animation?
if possible, explain as simply as possible, for a beginner!