minecraft-assets/assets/minecraft/advancements/story/follow_ender_eye.json

{
    "display": {
        "icon": {
            "item": "minecraft:ender_eye"
        },
        "title": "Eye Spy",
        "description": "Follow an Ender Eye"
    },
    "parent": "minecraft:story/enter_the_nether",
    "criteria": {
        "in_stronghold": {
            "trigger": "minecraft:location",
            "conditions": {
                "feature": "Stronghold"
            }
        }
    }
}