I’ve been working with dogs for over 40 years, owning, medicating and grooming. Even when I downsized and got my first toy dog (chihuahua) I never had a problem giving a pill.
Squeeze between the gaps of their teeth(on the side), place 1 or 2 fingers on the tongue and press gently. Voila! Mouth pops open by reflex. Put the pill as far back on tongue as possible. Hold mouth closed, stroke throat until you think they have swallowed. If the dog licks his lips with his tongue, you can be confident that your dog took the pill. For the more stubborn who seem to hold pill in throat indefinitely, a small puff of air in face caused a reflexive gasp and down went pill!
And then I got my first Brussels Griffon!