Fleural is not in the dictionaries as it does not exist. You won't find it in the UK Oxford or Cambridge Dictionaries, nor in the U.S. Merriam-Webster Dictionary. There is a town by that name in an online game, I believe! Don't use the word fleural. However, you can guess what the writer means: from the French word FLEUR we have FLOWER. A flowery smell. I think the writer has taken the French word, added -AL, got FLEURAL, and hoped we would understand. FLORAL would be a less confusing choice.

The word "Fleural" comes from Latin and means something like "Floral". From Latin Flōrālis pertaining to Flōra. "I really like this fleural smell" -> "I really like this flowery smell".