Enable + and - when viewing PR changes in Intellij

I use IntelliJ IDEA 2024.1.6 on Windows x64 to review the code of a GitHub pull request. I use the GitHub plugin bundled with IntelliJ. I want to be able to see a '+' when a line is added and a '-' when a line is deleted in the file I am reviewing. How do I configure Intellij or the github plugin to achieve this? Thanks in advance for your effort to help.