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

{
    "display": {
        "icon": {
            "item": "minecraft:shield"
        },
        "title": "Not Today, Thank You",
        "description": "Deflect an arrow with a shield"
    },
    "parent": "minecraft:story/obtain_armor",
    "criteria": {
        "deflected_projectile": {
            "trigger": "minecraft:entity_hurt_player",
            "conditions": {
                "damage": {
                    "type": {
                        "is_projectile": true
                    },
                    "blocked": true
                }
            }
        }
    }
}