Move files with modern authentication

Question

I need to move a file from one site collection to another with CSOM. There is a working sample here.

Move files with csom

When running the code I get an 401. It must be related to using modern authentication. Anyone knows how to do the same with modern auth?

var sourceSite = "https://xxx.sharepoint.com/sites/afd-286-oprydning-test-source";
var targetSIte = "https://xxx.sharepoint.com/sites/afd-286-oprydning-test-target";

var ctxSource = ClientContextExtension.GetAppContext(sourceSite, _config.AppRegistrationId, _config.AppRegistrationKey, "SaveToExcel", new EmptyLogger());
var ctxTarget = ClientContextExtension.GetAppContext(targetSIte, _config.AppRegistrationId, _config.AppRegistrationKey, "SaveToExcel", new EmptyLogger());

Web destWeb = ctxTarget.Web;
ctxTarget.Load(destWeb);
ctxTarget.ExecuteQuery();

Microsoft.SharePoint.Client.List list = ctxSource.Web.GetDocumentsList();
var item = list.GetItemById(1);
ctxSource.Load(item);
ctxSource.ExecuteQuery();

 if (item.FileSystemObjectType == FileSystemObjectType.File)
 {
     var file = item.File;
     ctxSource.Load(file);
     ctxSource.ExecuteQuery();

     var destLibrary = "Delte dokumenter";

     string location = destWeb.ServerRelativeUrl.TrimEnd('/') + "/" + destLibrary + "/" + file.Name;
      var stream = file.OpenBinaryStream();
      ctxSource.ExecuteQuery();
      Microsoft.SharePoint.Client.File.SaveBinaryDirect(ctxTarget, location, stream.Value, true);
 }

Answer 1

Found a solution:

var sourceSite = "https://xxx.sharepoint.com/sites/afd-xxx-oprydning-test-source";
var targetSIte = "https://xxx.sharepoint.com/sites/afd-xxx-oprydning-test-target";

var ctxSource = ClientContextExtension.GetAppContext(sourceSite, _config.AppRegistrationId, _config.AppRegistrationKey, "SaveToExcel", new EmptyLogger());
var ctxTarget = ClientContextExtension.GetAppContext(targetSIte, _config.AppRegistrationId, _config.AppRegistrationKey, "SaveToExcel", new EmptyLogger());
var targetLib = ctxTarget.Web.GetDocumentsList();

Microsoft.SharePoint.Client.List list = ctxSource.Web.GetDocumentsList();
var item = list.GetItemById(1);
ctxSource.Load(item);
ctxSource.ExecuteQuery();

if (item.FileSystemObjectType == FileSystemObjectType.File)
{
    var file = item.File;
    ctxSource.Load(file);          

    var stream = file.OpenBinaryStream();
    ctxSource.ExecuteQuery();

    string location = targetLib.RootFolder.ServerRelativeUrl.TrimEnd('/')+"/" + file.Name;               

    var fi = new FileCreationInformation();
    fi.ContentStream = stream.Value;
    fi.Url = location;
    fi.Overwrite = true;

    targetLib.RootFolder.Files.Add(fi);
    ctxTarget.ExecuteQuery();
}