You’re writing in HTML, so the Wix documentation you’re referring to doesn’t apply. If you were using Corvid then Wix would translate the URL you’ve reproduced here to a standard http URL but since you’re outside of Corvid you have to do it yourself.
https://www.wix.com/corvid/reference/wix-media-backend.mediaManager.html
The above functions should give you a rigorous method of retrieving the correct public URL but it might also be possible to do simple string manipulation once you understand the scheme used to build these URLs.
If it’s just one or a handful of images that will remain the same, you needn’t worry about any of this.
https://support.wix.com/en/article/retrieving-the-url-of-an-image