Hi Leon,
Living individuals who have taken a DNA test and would like to share their DNA test info here must join WikiTree at least as Family Member (agreeing to WikiTree's Privacy Policy and Terms of Service) and add their own DNA test info to their profile. After joining and entering their DNA test info, they can make you a manager of their profile, if they desire.
If your relative is deceased, and if you manage their DNA test info and their WikiTree profile, you can add their DNA test info to their profile.
See the DNA FAQ.