My organization isn't currently using SharePoint 365, but I've been able to successfully upload files to SharePoint by using a file Save As macro that uploads to SharePoint. If you can manually save a Excel workbook to your SharePoint location, then this method has a good chance of working for you. I recommend using the Export widget to trigger a macro that does the SharePoint upload for you at the end of your automation. Here is sample of the macro that you'll need to get you started.
Dim PreviousMonth As String
Dim Currentdate As String
Dim ServerLocation As String
Dim Extension As String
Dim POLine As String
Currentdate = Now
PreviousMonth = Month(DateAdd("m", -1, Currentdate))
PreviousMonthYear = Year(DateAdd("m", -1, Currentdate))
ServerLocation = "sssteams.providence.org/.../OSCM IS Reports/"
Extension = ".xlsm"
POLine = "PO_Line_Data"
Application.DisplayAlerts = False
ActiveWorkbook.SaveAs Filename:= _
ServerLocation & POLine & PreviousMonth & PreviousMonthYear & Extension, _
FileFormat:=xlOpenXMLWorkbookMacroEnabled, CreateBackup:=False
I hope this helps