@NextScripts
For obvious reasons, it would be helpful if the Medium instructions and/or the settings panel on the plugin, actually mentioned what the callback URL is. I’ve only found it thanks to this forum posting complaining that it was broken.
For those wondering, the correct URL is http:// or https://YOURDOMAIN.COM/wp-admin/admin.php?page=nxssnap (include HTTPS or HTTP on the front of that, as per your site).
