If you want to heal characters in Pathfinder: Wrath of the Righteous, there are multiple ways to go about it.
The first is to use health potions that can be purchased from merchants and found as loot to heal a small bit of HP to a large amount depending on the potion.
Equip these to your belt, and you can click your accessory tab on your item and skill bar to use them while in battle or outside of it. You can also use potions by right-clicking them inside your inventory and hitting use.
Another way to heal characters is to use both healing skills and scrolls, such as heal minor injuries to major injuries. Other skills and scrolls can also have healing effects, so of which can affect multiple characters.
Certain classes like the oracle and clerics also excel in providing healing spells for your party, and certain companions such as Darean are good characters to have for healing.
The last method of healing in the game is to rest by making camp. Resting can both heal injuries, debuffs and give your characters buffs if you have someone cooking food. It's also recommended to rest at major settlements and your camp to fully heal your party of corruption.
Check out our other Pathfinder guides for more help with the Pathfinder series!