Mobile site redirection from web site

I am using Contao 2.9.5 .How do redirect to my mobile site from my web site when user enter website url like http://www.example.com. Can any one help me out.

Note : I have tried out some plugins like "browser detection" and "redirect". But it is not helpful to me. It works locally not in live.

If it works locally but not live there may be something else wrong. What is the difference between the two setups?