型別別名：BearerAuthErrorCode (Type Alias: BearerAuthErrorCode)

type BearerAuthErrorCode = 
  | "missing_auth_header"
  | "invalid_auth_header_format"
  | "missing_bearer_token"
  | "invalid_issuer"
  | "invalid_audience"
  | "missing_required_scopes"
  | "invalid_token";