There used to be a "share" dialog with the ability to print QR codes, send them by email or copy the. This is gone. Going into the account setting page is hit and miss with all its bugs.
This project is unfortunately no longer maintained. If a new maintainer wants to step up and take care, the project is archived here: https://invent.kde.org/network/ring-kde You can just clone it in your private namespace on invent.kde.org and if you have started to work on it and fixed/implemented something get it reviewed and the project unarchived. Sorry for the inconveniences.