Hello everyone.
I am using the financial template to build my website.

I want to change the default background image, I have alredy red the guides but they didn't help me.

I want to change this background photo
https://prnt.sc/y10dlg

With this
https://s1.1zoom.me/big0/167/376131-alexfas01.jpg

Sometimes in the preview works the changing, but later when I upload the websitem it doesnìt work anymore. Why?

This is my windows where I am trying to change the default one:
https://prnt.sc/y10qrj

I also tried to change it here:
https://prnt.sc/y10uqh

But with the same results, it didn't work
How can  I change  it?

My website: https://grizzlymarketing.it/