If liquid doesn't work, I used to take one of my cats to the vet every day to have them do it. They are pros! Partly because the cat is scared. If she won't eat her food with it, try lifting her lip and squirting it in
Just double checking- try adding it to her food first. One time I took her to a best friends pet resort. They were trying to put it in her mouth, not food. So they gave up. I called 3 days later. She had started throwing up. They didn't know what to do. Instructions were typed on a piece of paper and the resort is right next to a vets! I know you are much more responsible than that! No more resorts. A friend took care of her. She is lucky to have you
So update: finally got the liquid prednisolone yesterday and gave him some last night. Predictably he was as agreeable to that as the pill, but it all went down his gullet. This seems repeatable, so hopefully he’ll start feeling better!