I want to comment multiple lines in a commit. I googled for that and found multiple instructions that all mention that one have to click the blue plus icon like here or at How to select/comment on a range of lines in github pull request?:
However, when I hove over this section with my mouse, no blue icon appears. I tried it in Chrome and Firefox (using Ubuntu 20.20).
Any chance that I can select multiple lines without the icon? Or what can I do to enable the icon?

