I run 1password across Windows 10, iOS and El Capitan, all of them with Pro licences.
In Windows (v18.104.22.1684) it's not possible to add or modify custom fields or sections in an Identity item. It's also not possible to see the custom section headings.
I have put some images on imgur - https://imgur.com/a/Jq5A3
P.S. When creating an agilebits.com login on the iOS app it asks for username/password, but the site asks for email/username/password.
1Password Version: 22.214.171.1244
Extension Version: Not Provided
OS Version: Windows 10
Sync Type: Not Provided
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