Use ImageSharp.Web in client websites requesting images (with commands) to another domain (media website)

[utilsites]

I have 2 client websites that need to request images (with commands) from a media website.

I configured ImageSharp.Web on the client websites and also in the media website.
On the client websites, the ImageSharp.Web TagHelpers works well only if I use:
<img src="//mediadomain/image.jpg" imagesharp-width="100" ...> (src URL starting with //, without using http:// or https://).
Because ImageSharp.Web TagHelpers ignore the commands if the domain is different from the current website and the URL has the protocol.

I searched in the issues and found a related post, but the solution is not clear to me, at beginning I was expecting to have the ImageSharpMiddlewareOptions.IgnoreHost configuration, but it seems the implementation went another way related to the cache keys? Not sure if it fits what I need, or it's a different problem, and how to configure ImageSharp.Web, can someone help please?

Note: in dev I also need ports on the url.