curl --request PATCH \
  --url https://api.loyaltylion.com/v2/customers/{merchant_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "customer": {
    "birthday": "<string>",
    "blocked": true
  }
}'

{
  "customer": {
    "id": 123,
    "merchant_id": "<string>",
    "email": "<string>",
    "points_approved": 123,
    "points_pending": 123,
    "points_spent": 123,
    "properties": {},
    "metadata": {
      "shopify_source_url": "<string>"
    },
    "rewards_claimed": 123,
    "blocked": true,
    "guest": true,
    "enrolled": true,
    "enrolled_at": "<string>",
    "referral_id": "<string>",
    "referred_by": {
      "id": 123,
      "merchant_id": "<string>"
    },
    "loyalty_tier_membership": {
      "started_at": "<string>",
      "expires_at": "<string>",
      "manual": true,
      "loyalty_tier": {
        "id": 123,
        "name": "<string>",
        "number": 2,
        "default": true,
        "hidden": true,
        "lower_bound": "<string>",
        "upper_bound": "<string>",
        "position": 1
      }
    },
    "insights_segment": "At Risk",
    "birthday": "<string>",
    "referral_url": "<string>",
    "linked_merchant_ids": [
      "<string>"
    ],
    "created_at": "<string>",
    "updated_at": "<string>"
  }
}