To set up the Trade Offer URL follow the next steps.

Step 1.

Log in on the site (How to log in?)

Step 2.
Go to "My profile" page.

Step 3.
Press the "Steam trade URL" link.

Step 4.
Copy the Steam Trade URL from opened page (you have to be authorized on Steam community site).

Step 5.
Paste the link in Steam Trade URL field on your profile page.

Step 6.
Save changes.