Always true: the URL is built without opening the file.
The fb2k://artwork/?path=... URL; not a data URL, only the component's WebView2 resource handler resolves it.
The path as given.
Always true here; a failed call resolves with ApiFailure instead.
The type the URL carries: front or back for their cover_ spellings.
Successful response from
artwork.getFb2kUrlByPath.