Use chrome inspector to determine the class name of your fixed header
Fixed Header Excel. Select the view tab, find the windows panel and click the button labeled freeze panes in it.
Select the view tab, find the windows panel and click the button labeled freeze panes in it.
Select the view tab, find the windows panel and click the button labeled freeze panes in it. Select the view tab, find the windows panel and click the button labeled freeze panes in it.