Chek the below steps,
→ Use the Excel application scope and give the path of the excel file.
→ Inside Excel application scope activity insert the Get workbook sheets activity and create a variable in the Sheets field in properties as List_Sheets.
→ Then use the below expression to get the last sheet name in an excel.
List_Sheets.Last.toString
These are the Classic activities you have to enable the Classic options in the Activities panel filters.
Check the below image for better understanding,
Hope it helps!!