As per your requirement the changes has been completed in your website.
I have created 15 sidebar to use widgets
sidebar1, sidebar2, sidebar2, sidebar4, sidebar5 ………………. sidebar15
Now add / edit the page and select ‘Extra Sidebar’ Page Template from right side
In Expert section type sidebar1 (the sidebar which you want to use)
You can create as many pages like this and use sidebar1 or sidebar2 ……… sidebar15 in Excerpt section (should be in small letter)
Also please select ‘Extra Sidebar’ Page Template if you want to use some extra sidebar .
Please check your website. The detailed documentation is also send on your mail id.