You don't download your DNA information into WikiTree. All you do on WikiTree is enter the fact that you took a DNA test. To do that, from the dropdown list on the 'Add' link at the top of your profile, select 'DNA Test Information'. That will take you to the page where you can enter information about your 23 and Me DNA test.
You should also submit your DNA results to GEDMatch.com so that you can compare your DNA with people who tested with Ancestry and with Family Tree DNA's Family Finder test.