Invocation - Firebrand

This is not really a feat, but rather a Warlock invocation.

Your Efreeti Genie Patron has granted you the boon of flame.

Bonus Cantrip
You learn the  Fire Bolt cantrip. It counts as a warlock cantrip for you, but it doesn't count against your number of cantrips known.

Expanded Spell List
All spells, from cantrips up to level 5 that deal fire damage are added to the warlock spell list for you.  If one of these added spells gives you a choice of multiple damage types, you may only choose fire.  A spell that deals multiple types, one of which is either predetermined to be fire or you may choose to be fire is added to the list; but again, you must choose fire at least once when given a choice of damage types.  A spell that deals random damage types, such as Chaos Bolt is not added to the list.