Can you put Fire Aspect on a bow?
No. You can't put Fire Aspect on a bow in Bedrock 26.60, not even with an anvil.
Why not
Fire Aspect is not on the bow's list. Here is what a bow can take instead: Curse of Vanishing, Power, Flame, Punch, Unbreaking, Infinity, Mending.
What that means in practice
Fire Aspect triggers on melee hits, while a bow does its damage through arrows. That is why the game gives bows a separate enchantment for the same effect. Flame has a single level, and it works with Power, Punch, Unbreaking and either Infinity or Mending.
What to use instead
The bow has its own fire enchantment: Flame. It sets your arrows on fire, so every hit burns the target, and it can light TNT from a distance. On a fresh bow, Flame costs 2 levels and Power V costs 5 levels as a book.
Flame and Fire Aspect do the same job in different ways. Flame lights your arrows, so it works at range and needs only one book. It also ignites TNT and campfires from a distance, which Fire Aspect can't do.
Why the game says no
Fire Aspect only goes on sword, spear and mace. A bow is not on that list. That matters because Bedrock checks a built-in list of items for each enchantment. So the anvil gives no result, and the enchanting table never offers it.
No survival trick changes that. Combining two items, renaming or using a grindstone first all leave the list the same.
The best bow build instead
So a max bow has Power V, Flame, Punch II, Unbreaking III and Mending. In the cheapest order it costs 26 levels over 5 anvil steps, and no step goes above 9. Open it in the calculator.
The best bow enchantments page explains every book, and the bow enchant order shows each anvil step.
Where Fire Aspect goes
- Fire Aspect goes on sword, spear and mace. Books on an anvil work on all of them. Related questions: Fire Aspect on mace, Fire Aspect on axe.
Commands and creative mode
The /enchant command refuses too, because a bow can't take Fire Aspect. Bedrock's /give can't add enchantments, so there is no way around it. The command generator writes the right syntax for your edition.
Java and Bedrock
As far as the item list goes, the answer is also the same in Java and Bedrock. The anvil differs, though: Bedrock only charges for the levels a book adds. This page follows Bedrock 26.60.
About Fire Aspect
Fire Aspect sets the mob you hit on fire. Burning mobs take extra damage over time and drop cooked food.
Fire Aspect has a max level of II. If you need a book, you can get it from the enchanting table, librarian villagers and enchanted loot from fishing and chests. Before you buy, read everything about Fire Aspect, including what each level does.
What else a bow can take
Instead, a bow can take Power, Flame, Punch, Unbreaking, Infinity and Mending. Then the best bow enchantments page ranks them and gives the max build.
Related questions: Mending on bow, Mending and Infinity on bow.
Questions
Can you put Fire Aspect on a bow?
No. You can't put Fire Aspect on a bow in Bedrock 26.60, not even with an anvil.
What else can Fire Aspect go on?
sword, spear and mace.
Is Flame the same as Fire Aspect?
Both set targets on fire. Fire Aspect works on melee hits and Flame on arrows. Flame has a single level.
Can a crossbow have Flame?
No. Crossbows take Multishot, Piercing and Quick Charge, but not Flame.
Can a bow get Fire Aspect from an enchanting table or a villager?
No. The enchanting table only offers enchantments an item supports. A villager's Fire Aspect book still can't go on a bow, because the anvil checks the same list.