Facebook messenger bot- am not able to close the window on click of button

Question

I'm navigating from messenger bot to url link("https://xyz.xyz.com/Facebook/apps/Facebook/common/views/Enquiryloans.html") after opening this page in the browser i need to close this using onclick javascript function. But i'm not able to close this page (error in the console is :Enquiryloans.html:349. Scripts may close only the windows that were opened by it.)

I tried:

{ window.open('', '_blank', ''); customWindow.close();}

But that window is not closing.

Thanks in advance