the power that governs bonus spells is determined by which kind of spellcaster your character is: Intelligence for wizards; knowledge for clerics, druids, paladins, and rangers; or Charisma for sorcerers and bards.
In https://hannamtgn676738.articlesblogger.com/55847165/how-much-you-need-to-expect-you-ll-pay-for-a-good-d20