Export grouped ag-grid row data to excel using native excel row groups

I have an ag-grid with row grouping and am exporting to excel. The client wants the data in the resulting excel file to be grouped using Excel’s native row groups.

I see in the ag-grid documentation that they provide a way to style row group names using processRowGroupCallback, but I don’t see any way to map row groups to Excel row groups.

Am I missing something? Is this possible? Or would you essentially have to write your own excel export functions from scratch, and know the inner working of excel file format and the implementation of row grouping there?