The link works in many ways:

1. if you type some URL such as google.com, it will automatically converted into a link
2. paste a link or a link-with-text into the editor will create a link
3. select some text and click the add link button

To edit a link, click on the link, there will be two buttons: edit link and remove link.

To open the link, right click and select "open link in new tab".

Reference: https://remirror.io/docs/extensions/link-extension/