Open Pokémon GO
Tap the Poké Ball menu
Tap Pokémon
Select the injured Pokémon
Tap the Potion item from your Bag
Tap Use
Repeat with more Potions if needed
Use a Super Potion, Hyper Potion, or Max Potion for larger healing
Use a Revive or Max Revive if the Pokémon has fainted
Use a Pokémon Center? Not available in Pokémon GO