In the options for pivot table you can use Count instead of Grand Total as Summary. However, you will have to choose between the Grand Total and Count. If you calculate the grand total in some other way (for example by placing another [Outlet].[H1].[Region].Members and then Gear icon > Compute Aggregate > SUM), that COUNT will also count the cell with the Grand Total.
Otherwise you can create a "Row Number" calculated measure with the expression below and place it on measures next to Revenue