That is correct, find the hole and put a plug in it. If it is on the side wall, plugs don't work very well. Slime tire sealant, or similar works a little better for side walls and around leaking beads. Just don't use fix-a-flat because unless they changed the formula is corrosive.
Plug it that sealant makes a mess of the wheel inside just over inflate it a little, and spray it with water to find the leak, and plug it or if you have a local discount tire shop they will fix it for you cheap. I have had some mounted there, and repaired they dont charge much if anything at all.