Background Img fixed position movable?

Hi i love your theme vantage it is the best i have just one thing i would like for it to have like in some other themes i found some of them have backgrounds in the middle of a website page and when u scroll down the picture moves like in this theme = “https://wordpress.org/themes/zerif-lite” in the bottom of this theme “get in touch” .

I want to make the same effect only using your vantage theme because in my opinion it is better for customizing and an overall feel of the theme. Can you help in this regard do u know how can i do that and if it is possible whit your themes.

Thank you in advance
Best Regards
Žiga