I'm currently building a tool to migrate from a document management system to use SharePoint Online. The main challenge I'm facing is to preserve the details of document authors and creating time. I have checked bunch of of code online but I didn't get success with any of them. Here are the approaches I used
- SharePoint Rest API
- Microsoft Graph API
- CSOM (using console application)
Here is the code I have so far in CSOM but I'm still not able to update the Author field
li["Title"] = "Update from CSOM";
li["Created"] = DateTime.Now.AddYears(-5);
li["Author"] = author.Id;
li.UpdateOverwriteVersion();
clientContext.ExecuteQuery();
Any idea for how to do this, or if there is any other approach to achieve my goal?