Mailchimp Custom HTML not displaying background image in Outlook

I purchased a custom HTML newsletter template from Envato to use in our Mailchimp account. Everything works within the template except I can not get the header background image to display in Outlook365 behind the text. I have to assume it’s possible because I receive other newsletters from larger brands that do exactly what I’m trying to do. Any idea on what code I’m missing?

If it helps, here is the template that I purchased: crypto

Outlook (depending on the version) notoriously cannot load background images

Are you sure that the ones you have seen doing it are not just using standard images with the text on them not as a separate layer?