After you have enable the multilingual and configure the default and available languages, you may want to set a language switch in the front end site.
All the Url, parameters and routing will be rendered by Kooboo automatically, what you need to do is providing a link where user can switch their language.
If you enable the SitePath option in the system setting, your language indicator is at the path, your switch may looks like below
<ul> <li><a href='/en/mypage'> English</a></li> <li><a href='/zh/mypage'> Chinese</a></li> </ul>
If you did not enable the Site Path, the language indicator will be set in the Url, to switch the language, you can use code below.
<ul> <li><a href='/mypage?lang=en'> English</a></li> <li><a href='/mypage?lang=zh'> Chinese</a></li> </ul>