Wikitree doesn't record DNA results, just the fact that you took a test. Go to your own profile and at the upper right click on "Add." The first item you see will be "DNA Test Information." Click on that and on the DNA page you will see a place to Add New Test Information. There is a drop-down to select your test. Enter and save that information. In about 24 hours the information will propagate backwards to your ancestors. If you want to upload the actual DNA details you'll need to use a site like Gedmatch.