First of all, make sure that you have an active PREMIUM subscription, Skinchanger won't work without it. Go to your profile on the site: there is a SKINCHANGER tab where you can select a skin by clicking on it. If you have PREMIUM active, and this functionality does not work, press CTRL+F5.

A stroke appears around the cell of the selected skin. If there is a stroke around the skin on the site, but it is not displayed on the server, then you need to make sure that you are authorized on the site and in the Steam app on your PC from the same account.

Before contacting support, we strongly recommend that you reset your skins and repeat our recommendations.