Can not close webpage after redirect to LIFF url

How to close webpage after clicking to the http link and redirect to liff url?

 problem create step:     1. Create a webpage and send it to user.

 2. User click to https url in chat screen 

  3. Webpage A has been loaded and some logic has been executed. After that, call liff.openWindow() api to start page B

 4. User click to "X" at the top right of window to close liff window.

 => Webpage A (blank page) still there and can not be closed. If want to close webpage A, must click to "X" at the top right again :(

How to close page A after close liff window or close page A before open liff window?

Thanks any help m(_ _)m.