In SAP Datasphere, the expression you've provided uses the function `FormatDate` combined with `RelativeDate` and `DayNumberOfMonth`. To validate your expression, ensure that you're following the correct syntax and conventions used within your specific SAP Datasphere context.
Your expression, as is, appears to be aiming to format the last day of the previous month in the "yyyyMM" format. However, to ensure it validates properly, it’s important