Resizing header image

we cant find what element rule this header image we try everethink please help we need control it (change size) to perfome best on mobile

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Hey @Webfff! The header image can be found as a background image of the “header” component:

You can play around with the settings to make it looks better on mobile: