How can I read dynamic excel files?

I am reading excel files from SharePoint, but some time the excel file may add some useless column for my flow (just useless for me but useful for someone else)

I want to use the “Transformation” tab to determine the column type, and try to unselect the “any unknown new column” to avoid the error. But it doesn’t work. I understand I can select the “Use new schema” option, but if I select it, I cannot configure the column type in “Excel Reader”.