development – Upload a file in any specific subfolder of sharepoint online C# (CSOM)

I am trying to send a file (Test.docx) to a specific folder under document library in sharepoint online. The folder name is “new” which is under a “Test” folder i.e. Documents/Test/new. Now, there could be additional subfolder under “new” folder where I want to send that file.
I have tried with attached code, but it is not working. I can send file to “Test” folder with current code but not in subfolder of it in “new”, and getting execption like “Microsoft.SharePoint.Client.ServerException: File Not Found”. Is there a simple way to do that with my current code? Thank you!

            using (var clientContext = new ClientContext(""))
                clientContext.Credentials = new SharePointOnlineCredentials(username, securePassword)

                Web web = clientContext.Web;
                FileCreationInformation fileCreationInformation = new FileCreationInformation();
                fileCreationInformation.ContentStream = new MemoryStream(fileBytes);
                fileCreationInformation.Url = "Test.docx";  
                List documentLibrary = web.Lists.GetByTitle("Documents");  //get document library
                Folder destinationFolder = null;
                string destinationSubFolder = subFolder;  //specify subfolder

                if (destinationSubFolder == "")
                    destinationFolder = documentLibrary.RootFolder;
                    destinationFolder = documentLibrary.RootFolder.Folders.GetByUrl("new"); //when it is a subfolder

                Microsoft.SharePoint.Client.File uploadFile = destinationFolder.Files.Add(fileCreationInformation);