adding banner image - Skye template

Hello! I'm new to Squarespace and creating a blog. I'd like to add an image or banner above the blog section of the home page. I'm using the Skye template and like the examples shown such as ALYCE ALEXANDRA and MUSEE where they have an image above the blog section. I've looked for that 'banner tab' and can't find it and can't seem to add an image block. I've tried adding a page above my blog page but i'd like to just scroll directly down to the blog section without navigating to another page. 

Thanks for any info you can offer!

@rmjs you can use custom code, not really good way.

Add to Home > Design > Custom CSS. Replacy https://...generatepress.png with your banner image url

.homepage div#blogList:before {
    display: block;
    content: "";
    background-image: url(https://beaverhero.com/wp-content/uploads/2019/10/target-generatepress.png);
    background-repeat: no-repeat;
    background-size: contain;
    height: 400px;
    margin: 0 auto;
    max-width: 1150px;
    margin-bottom: 20px;
}