How to capture the error message

I want to capture the error message so I can do different actions depending on the text.  I can't figure out how to code this.  Here's my code...

        if DropboxClientsManager.authorizedClient != nil {
            print("We have an authorized client.  Now let's see if we can get the file attributes")
            
            // Check to see if Nvelopes.csv exists in Dropbox.
//            client!.files.getMetadata(path: "/Nvelopes.csv")
             client!.files.getMetadata(path: "/Nvelopes1.csv")
                .response {_ , error in
                    if let error = error {
                        print("We did not get the attributes :(")
                        print(error.description)
                        self.window?.rootViewController = mainStoryboard.instantiateViewController(withIdentifier: "sbLinkToDropbox") as UIViewController
                                            }
             }
            
        }

... and here's the result of print(error.description):

[request-id 7185a7cb73542868da1649971559a895] API route error - {
    ".tag" = path;
    path =     {
        ".tag" = "not_found";
    };
}

How do I capture the part after ".tag" =??

Thanks for your patience!