How can I turn on the mobile version?

The link for VK's mobile version is
Just type this address into your device's browser. There is no need to download or install anything.

You can get to the desktop version of the site by clicking on the "Desktop version" button found in the left-hand menu or by simply following this link (see screenshot).
Your search for returned no results.
Try using other keywords, e.g.: "delete profile", "create chat".
Check your request for misprints.