Are you using the legacy editor for the archive or the block editor? It wouldn't be possible to duplicate an archive created with the block editor, as it uses more than one post to record the custom archive.
But it might work with a legacy archive, where all the details are stored in a single post (and its post meta).
In that case you could try one of the many post duplicator plugins. I don't know for sure it will work, but expect it would.