custom_mc_advancements/data/locations/advancements/agent_p.json

{
    "display": {
        "icon": {
            "item": "minecraft:cyan_concrete"
        },
        "title": "Agent P",
        "description": "A platypus? (at spawn)",
        "frame": "task",
        "show_toast": false,
        "announce_to_chat": true
    },    
    "parent": "locations:landmarks",
    "criteria": {
        "be_near": {
            "trigger": "minecraft:location",
            "conditions": {
                "dimension": "minecraft:overworld",
                "position": {
			"x": {
			    "min": -54,
                            "max": -45
			},
                        "y": {
                            "min": 124,
                            "max": 131
                        },
                        "z": {
                            "min": -370,
                            "max": -362
                        }
                }
            }
        }
    }
}