The Funky Monkey Brew

This is a quest that requires you to complete the Scenario Unga Ingoo.
You find your scenarios in the Dungeon Finder (default key: I)
Alternatively, you can speak to the questgiver for an option to queue, as Farmbuyer added in below
Be aware that the quest turn-in area is a phased area, so the npcs do not load till you are relatively near, resulting in n o turnin ? on the minimap untill you are close.

You won't be able to use the NPC to queue for the Scenario directly if you're 100 (most likely it affects anyone above level 90). You'll have to head back to the Vale, specifically to the Seat of Knowledge, and use the NPCs there to queue for Normal or Heroic Scenarios (Raid Finder has an NPC also). More traveling involved, but thankfully we're still able to run this prior content.

I am trying to do this scenario, but I keep getting a message that I do not meet the requirements.

I am a level 100 with almost all the world quests completed.

Any idea what I am missing here?

Thanks,
BJR