I have a groom asset and have generated cards, I'm trying to test the hair card texture tool:

https://www.sidefx.com/docs/houdini/shelf/groom_haircardtexture.html [www.sidefx.com]

after clicking the tool on the shelf the only object, it looks like it will allow me to select is the hair cards, i do so and press enter, however, I get nothing but an error saying "No groom objects selected."

Not sure what I am supposed to do, and I cant really find examples using these tools.