Hi
You can use this custom css
.view-article #sp-main-body .container .article-details .article-header-wrap:after{
background-image: url(/centro/images/2021/06/08/fiore_large.jpg) !important;
}
Add this css code inside the custom.css file.
Note: Path towards custom CSS:
Extensions>Templates>Styles>
Click on your current default template name then choose Template Options.
Then find custom CSS within the custom code.
https://prnt.sc/pu705g
https://prnt.sc/pu70zn
In Extensions>Template> Template Options > Custom Code > Custom CSS please add this
Thanks