Based on the reports in the community answers, this is most likely how the attachment is intended to work: the wide-angle converter is designed to be used with the matching rear section attached, and removing that section turns it into a close-focus/macro element rather than a normal-focus wide converter.

So if the wide section alone won’t focus at normal distances, that’s expected. The “macro” part is not just optional support glass for wide-angle use; it helps make the combined unit focus properly on your lens.

As for the weak real-world widening and poor image quality, that also matches what others reported for similar low-cost screw-on converters. These attachments often don’t deliver their claimed magnification cleanly across the frame, especially on zoom lenses, and may only work acceptably over a limited focal-length range.

So yes: you likely need both pieces together for wide-angle use, and yes: the advertised performance may be optimistic. If you want reliable wide-angle results, a dedicated wider lens will usually perform much better than a front-mounted converter.