A refund REST API error has occurred.

All other Server APIs have been confirmed to be functioning properly.

When checking the SKU via viewer_purchases, refund_iap_entitlement returns the "error_user_msg": "We can't find your order at this time."

We are still in the development stage before the launch.
Thank you.

HTTP/1.1 400 Bad Request

{
  "error": {
    "message": "An unknown error occurred",
    "type": "OAuthException",
    "code": 1,
    "error_subcode": 1891060,
    "is_transient": false,
    "error_user_title": "\uc8fc\ubb38\uc744 \ucc3e\uc744 \uc218 \uc5c6\uc2b5\ub2c8\ub2e4",
    "error_user_msg": "\ud604\uc7ac \ud68c\uc6d0\ub2d8\uc758 \uc8fc\ubb38\uc744 \ucc3e\uc744 \uc218 \uc5c6\uc2b5\ub2c8\ub2e4.",
    "fbtrace_id": "APeiCD1VcJp0x3hE5hbRCev"
  }
}