I am new to GitHub. I am trying to make make many issues on my board and would like to play around with Linked Issues to learn how they work. The documentation says that I can click "Create Linked Issues" from the sidebar of an existing issue. But I cannot find that button. Am I missing something?

Here is a screenshot of an existing issue's sidebar. This was taken on MacOS and Brave browser. I also tried Firefox and Safari, in regular and incognito mode. I have not tried Windows yet.