minecraft-assets/assets/minecraft/advancements/end/levitate.json

{
    "display": {
        "icon": {
            "item": "minecraft:shulker_shell"
        },
        "title": "Great View From Up Here",
        "description": "Levitate for at least 30 seconds",
        "frame": "challenge"
    },
    "parent": "minecraft:end/find_end_city",
    "criteria": {
        "levitated": {
            "trigger": "minecraft:levitation",
            "conditions": {
                "duration": {
                    "min": 600
                }
            }
        }
    }
}