Father clip edge

I want to feather the edge of a clip. Everywhere online it says to use the motion tab, but I swear to all that is holy that there is no "motion tab" in my version of Final Cut Pro: 10.6.8. And there is no feather feature in the Video Inspector window. I can feather a mask, but I want to feather the edge of a clip that I have moved off-center. So ... How do I do this? I am certain that about 20 years ago, there was a feather feature for clips that was easy to find. How is it done now?