This Addon adds new furnaces to your game that work in a very different way.
The main fuel used in the furnaces is Redstone, it can give enough fuel to heat up 5 items. The redstone block can provide fuel to heat up 45 items
To add the fuel to the furnace, you just need to have it in your inventory and interact with the furnace, you can't be crouched if your intention is to fill the furnace with the fuel.
If you already have enough fuel and want to heat up your items in the furnace, you simply keep them in your inventory, and crouch while interacting with the furnace. When you do this, it will light up.
As long as it has fuel, the furnace will continue to heat up items, remembering that it gives priority to items from nearby slots, especially the Hotbar.
1 - Hotbar
2 - Slots of the top
3 - Slots of the middle
4 - Slots of the down