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

{
    "display": {
        "icon": {
            "item": "minecraft:ender_pearl"
        },
        "title": "Remote Getaway",
        "description": "Escape the island"
    },
    "parent": "minecraft:end/kill_dragon",
    "criteria": {
        "entered_end_gateway": {
            "trigger": "minecraft:enter_block",
            "conditions": {
                "block": "minecraft:end_gateway"
            }
        }
    }
}