浏览器“请求桌面站点”是返回移动设备

I have dynamic serving content for mobile site, so i have use same url but site is detect useragent and based on device i have display content.

Now i have problem when users click option in chrome "Request Desktop Site" my site is sitll detect useragent same as mobile and still display mobile site.

As i can see chrome does not change useragent when this option is checked in browser, i have test with php $_SERVER['HTTP_USER_AGENT'] and useragent is same. There is any way to redirect users to dekstop version, i can see some site do that, but i don't have idea how.