JXpress express said, you only have to enter in the actual ID and not the whole link.
Here's how to do it:
1. Go to your Pwned user Home Page
2. Click "Add/Delete Steam Community Account"
3. Enter in your Steam ID
EX. Me I entered in TheRealHades
4. Click Submit.
5. Give it a moment to refresh and if it was a valid name entered, you'll see the tag there.
6. It will populate on your actual Pwned page as well.
7. Enjoy Pwned.com
Hope that helps. 
"Those who say they don't fear Death are either Lying or Insane. Which am I?"
-Hades
God of the UnderWorld as well as the Erratics |