Betheme question about header

I am working on a website for a client and which uses the Betheme - there is a small grey arrow that appear at the top left of the browser. Can you tell me what this is call and where I find it to turn it off.


It’s better to contact the theme author regarding to forum(here) is for general purposes but not for item support

Thank you - I am a newbee at this forum. :slight_smile: