How to request a sponsorship letter from my employer ?

Hi,

I am looking forward to apply my UK visa in order to remain stay in UK. I'm working for this company as a permanent employee more than a year now and the recent conversation with my manager, She want me to write everything in written statement so that it can be more effective to speak to HR. Kindly please some one help me in this at the moment I'm on PSW(Post-Study Work).

I could be more grateful if someone help me on different legal way.

Thanks