Hi Phoenix!
Are you looking for a specific group or tradition related to fire, or more along the lines of magick that focuses on fire spellwork?
It might not be what you have in mind, but there’s a great elemental page exploring all about fire. I’ll link it here:
Fire is a very popular element, and there are lot of “fire spells” that draw upon specifically fire energy and the power of flame. Here are a few in case you’re looking to add to your fire magick collection 
- A Spell to Burn Away Obstacles 🔥
- Energy Spell: Boost Your Inner Fire
- Cinnamon Fennel Fire Tea
- Belenus: God of Light and Fire
- Dragon flame meditation
Fire elements could also be worth looking into, both Salamanders and Dragons 
Not to mention that all of the candles spells would also tie into fire magick, as well as Pyromancy/Flame Divination too.
When it comes to fire witchery, you’re in luck - there are a lot of resources out there for you! 
I hope you can find what you are searching for. Good luck and blessed be!