How can I add a background image to a code block?

Site URL: https://chihuahua-clarinet-zdjc.squarespace.com/config/

I want to add a textured background image to a code block that displays text on my home page.  How can I add the image to my website so that the url attribute in my background-image tag knows where to find it? 

SQSP has two general help articles on this:
(1) Uploading and Managing Files, and
(2) Creating a Text Link.

In each case the tactic is to upload the file, images only in method (1), capture the SQSP generated URL to the file and then use that URL in the code

<img>

Thanks, Derrick! This worked just fine, and now I know how to manage files in the future.