Yeah for the more ferocious fighters out there this would be extremely difficult to pull off but many house cats can be done this way.

You place the pill on the top of your index finger, right hand. Then you take the thumb and index finger of your left hand, form a C shape pincer with them, and then oinch at their gumline on either side to force their jaw apart. You’ll have a moment when their mouth is open and you can see their tongue - you have to poke that pill as far back on their tongue as you can. They will gag and recoil and lick lick lick the air, but hopefully the pill has gone down in that process.