Help!! How to see the variables on the Dialog window of my component

Hi everybody! A new user here

I would like your help to undestand the right way to create a variable from a excel file on my computer to be shown on the dialog configuration window of a component to be able to change the location of the file, depending of who is using the Knime WF.

Some screenshots of how I configured the variables and isn’t working

What am I doing wrong??

Thanks in advance!!