I found the same issue as the grass does need sunlight and not ideal to place on a windowsill for the cats to climb on in the window. I ended up having 2 pot planters on rotation. I’d put one outside for a few days, then swap.

Are you planting or potting it? We had two which we would rotate in and out of their cat enclosure. We grew them in the Catit Grass Planters so they didn’t have access to the roots.
I previously grew it in my hydro herb kit but they would absolutely destroy it when i gave it to them and was always back to step one.

Oh dear, sorry but I had to laugh at this. The lengths we go to so we have happy healthy pets

cannot seem to keep it alive either! I almost have to treat it like fresh cut flowers; disposable after a week or two