Number of closed invoices which doesn't include any product sale.
Validate in Zenoti
Zenoti -> Reports NEW (v2 report)-> Financial Reports -> Sales - Accrual report -> Select all values in Item Type, Sale Type and Payment Type dropdown -> select centers as displayed in ezPulse app
Unhide Invoice Closed Date and Status column
Export the report in excel, open the file remove top 5 rows and last row
Select the table and Go to Insert Tab -> Pivot table
Add Status in Filter and select Status as Closed. Select item type in Columns, select Invoice No in Rows and Select Count of Item Type in Values.
Now add a formulae in a new column =IF(ISBLANK(GETPIVOTDATA("Item Type",$A$3,"Item Type","Product","Invoice No",A5)), 1, 0)
Drag the formulae till end of the table
After this apply Sum on the rows of newly created column, the value shown there is the metric value