Tractor Supply, animal meds. I used horse paste green apple, brand name is Bimectin, its all same (Ivermectin 1.87%). It comes in a application syringe with 250 pound dosage ticks marked on the plunger.

I weigh 250, so I just squeezed out 1 dose as marked. 2 days later 2nd dose. 5 days after Covid-19 symptoms in chest, fully recovered, zero chest infection or congestion.