Backup and Restore of cloud DQL database

In your exportStatus query, the exportId argument should be "exports/2021-12-02/0x26d673b-1006229647":

query ExportStatus {
  exportStatus(
    exportId: "exports/2021-12-02/0x26d673b-1006229647",
    taskId: "0x1bd686d8f"
  ) {
    kind
    lastUpdated
    signedUrls
    status
  }
}