Retrieve loyalty details

curl --request GET \
  --url https://services.commercengine.dev/api/v1/x2yh61zw4k/storefront/customers/{user_id}/loyalty \
  --header 'Authorization: Bearer <token>'

{
  "message": "<string>",
  "success": true,
  "content": {
    "loyalty": {
      "membership_number": "<string>",
      "loyalty_tier": "<string>",
      "loyalty_point_earned": 123,
      "loyalty_point_redeemed": 123,
      "loyalty_point_balance": 123,
      "loyalty_point_redeemable": 123,
      "loyalty_point_bonus_accrued": 123
    },
    "loyalty_point_balance": 123
  }
}