currently Vuforia Studio supports only animation inside the pvz format and created in Creo Illustrate.
Animation should be embed inside a sequence step. I think at PTC there are plans to implement also the other animations e.g. based on creo .frm file (they could be created e.g. in Creo Mechanism and Creo animate) but so far, I know this is still no part of the current functionality
There is currently workaround how to import such animation into sequence step using to open Creo Illustrate session.
Back to your issue: - I think the only option ( I think it will not work but you can still try) is to try to import the animation in Creo Illustrate and try later to convert it to a sequnece step. The optimizer will not perform this task.
If you animation is based / embed in fbx file (from autodesk) - I think this file (the animation) will work fine in unity where you can use the vuforia engine as alternative way