Firstly, as I've answered in the community forum, you can't use a psd file as a background image. You will need to use an image editor that works with psd files to save it in png format. As the link in your question to the psd file doesn't work I've not been able to save the file for you.

Once you have saved the file as a png, upload the image to the css:global-css page. If you want the logo and a background image then you'll need to add the logo to the header-extra-div-1 class and position the logo as you want. In the example below from one of my test sites here I've hidden the site title and replaced it with a logo but you don't have to do that, you can show both.

/* Background Image */
header.header-wrap {
    background-image: url(/local--files/css:global-css/ronda.jpg);
    background-repeat: no-repeat;
    background-position: left top;
    width:100vw;
}
 
/* Title */
.site-title > h1 a span {
    font-size: 50px;
    visibility: hidden;
}
 
/* Logo */
.header-extra-div-1 {
    background-image: url(/local--files/css:global-css/classic_wines.png);
    background-repeat: no-repeat;
    height: 200px;
    margin-left: 55px;
    margin-top: -158px;
    width: 500px;
    z-index: 200;
}

Answer by RobElliott
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<Sorry to repeat the question I was meaning to take down the comment on the community site>

Answer by Joshua Darby
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