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

{
    "display": {
        "icon": "minecraft:shield",
        "title": "Deflect an arrow"
    },
    "parent": "minecraft:story/obtain_armor",
    "criteria": {
        "deflected_projectile": {
            "trigger": "minecraft:player_damaged",
            "conditions": {
                "damage": {
                    "blocked": true,
                    "is_projectile": true
                }
            }
        }
    }
}