First of all to connect to your server using web-VNC protocol you should login to VMmanager panel. You can login to this panel via Billing or just following the link that you have received to your e-mail after server was installed In this manual we consider login through the Billing. In your Billing account please open folder Virtual private servers in the left sidebar. Then select exactly server you need and press the button To panel (located on top).

After please select Virtual machines in the left side bar and then select the VPS you would like to login. After you need to precc VNC button in the top panel.

After it will open new folder with running VNC client. You will see the common login page of OS you have installed before.

 If you use Windows you will see normal login dialogue.