When I first rescued Lucy and her sons, they had flu and were unhandleable. The vet gave me abs in a solution. I put a couple of drops in their food, making sure they ate from their own dishes.
Ask your vet for abs in a solution (I think the vet nurses had a powder which they dissolved in a liquid when I picked up the abs). My ferals fell for this trick.
A trick I've tried, successfully, with a domestic cat, has been to give her some munchie treats (such as Dreamies or Thomas), about half a dozen of them, and include amongst these the abs pill. She just greedily ate the pill thinking it was a treat, only realising her mistake after she'd eaten it. This only works a few times and is best if alternated with other methods.
Another method is to hide the pill in something your cat loves. I had a cat, Samantha, who LOVED cheese, so I would wrap the abs in some cheese which I sort of molded round the pill. She would rapidly eat the cheese then suddenly have a surprised look on her face; but too late, she'd taken the pill! Again this only works a few times and is best alternated.
The drops on food is the simplest method I've used, but you'd need to ask your vet about this. My vet at the time knew I was treating ferals.
Good luck.