How can i achive setting visible background-image on this tag?

I want to make copy to this
but how can i set background-image to header tag. I tried some check-in-off in inspect element to disable attributes and other but cant figure out how…
Here is my codepen. Background image on header tag is not visible, why that, and how to fix it?

Hey, you have to give the header a width and a height.

header there is min-height: auto
And when i disable it nothing change?
So don’t think it is that, if u can pls show me that on the pen


How then on this link height is auto and width 100%?

It has min-height: 100%;

Sry i was looking website in 720 x 965, there is not min-height