The first time you open an Unreal Engine project, you'll see a notification that the RiderLink plugin is missing. You can select a specific version, or just select Rider to always use the latest installed version. Once the plugin is installed into the engine and enabled, Unreal Editor will list JetBrains Rider as a supported source code editor ( Editor Preferences | General | Source Code). For details, refer to the plugin page on GitHub. If you’re using an earlier version of Unreal Engine, you need to install the RiderSourceCodeAccess plugin manually.
Starting with 4.25 on Windows and 4.26.2 on macOS, Unreal Editor has built-in support for JetBrains Rider with Unreal Engine features. Xcode command line developer tools (to install, use the xcode-select -install command)