SpreadsheetSetCellValue not setting as a number in excel

I’m getting an interesting error when trying to use the setRowHeight function:

can’t call method [setHeightInPoints] on object, object is null

I’m implementing the function as follows:

local.spreadsheet.setRowHeight(workbook=local.workbook, row=1, height=60);

Was wondering if you had any ideas on this? @Julian_Halliwell

Thanks in advance!