Function invalid_request_type 

fn invalid_request_type(
    err: &SendAccessTokenError,
) -> Option<&SendAccessTokenInvalidRequestError>

Extracts the typed send_access_error_type from an invalid_request response, or None if err isn’t that shape. attempt_access and access_with_email_otp both need to branch on this one sub-field of a deeply nested error enum; centralizing the match here keeps those call sites down to a single Some(...) => ... comparison instead of repeating the full pattern.