Go to the gear at the top right of the screen. Drop down to 'profile info', and click it. Once you get to that page, there should be an option to add a URL for a buy/sell/trade list.
[quote name='Dark Rider']Go to the gear at the top right of the screen. Drop down to 'profile info', and click it. Once you get to that page, there should be an option to add a URL for a buy/sell/trade list.[/QUOTE]