Do you want to enable/disable Back to Top button ? If so, here are simple instruction.
First of all Go To: WordPress Admin > Appearance > Customize > Business Press Options > MISC Options.
Now you can click on MISC Options. Here you will see a toggle button for Back to Top. It use to enable/disable back to top icon of your website.
If you will turn it on, then Back to Top icon will be enabled on front end website.
Thanks and Enjoy !!