Use rollup to calculate grand totals with grouping

I have a stored procedure:

ALTER PROCEDURE GetReportData
AS
BEGIN
    SELECT 
        LOC.SubCompanyNameVN,
        LOC.BranchName,
        COUNT(LOC.BranchCode) as Total,

        ----------- Not Processed Yet
        SUM (CASE WHEN SS.Status IN (5, 6) THEN 1 ELSE 0 END) AS CountNotProcessedYet,
        
        ----------- Processing
        SUM (CASE WHEN SS.Status IN (3) THEN 1 ELSE 0 END) AS CountProcessing

    FROM 
        DBO.WorkingSession AS SS
    JOIN 
        DBO.Location AS LOC ON SS.LocationID = LOC.LocationID 
                            AND SS.BranchCode = LOC.BranchCode
    JOIN 
        DBO.Status AS ST ON SS.Status = ST.ID
    GROUP BY 
        LOC.SubCompanyNameVN, LOC.BranchName
    ORDER BY 
        LOC.SubCompanyNameVN
END

The result:

But now I expect my result to be:

How can I group the results by column SubCompanyNameVN (Group By SubCompanyNameVN) to calculate the total like the above table? I have researched and I think I can solve it with ROLLUP but I am confused about it.