As I cannot use Pnp.PowerShell with a SharePoint-2019 on premise, AFAIK, I’ve been trying to do it with OData using curl. Unfortunately it happens to be much more complicated than I thought. I ended up building this command: curl -vvv -n -X POST "https://sharepoint.site/site/aaa/_api/web/GetFolderByServerRelativeUrl(‘/site/aaa/library/folder’)/Files/add" -T a.xlsx -H "Accept: application/json;odata=nometadata" -H "X-RequestDigest: xxxxxx" HTTP/1.1 400 Bad […]