Attempting to load the following page [1] with Firefox 113 returns the following error when it attempts to load the image:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://w.wallhaven.cc/full/z8/wallhaven-z8rkew.jpg. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing). Status code: 403.
[1] https://wallhaven.cc/w/z8rkew
Looks like you need to add the parent domain to the CORS header for the image host.
https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS/Errors/CORSMissingAllowOrigin