Bgr Background Render adds background rendering to Blender. After saving the current file, you click 'Render Image' or 'Render Animation' from the properties panel and continue with your current creation while the render runs and completes in the background.
Holding Ctrl when triggering a render opens the options. You can use the current frame and output path, or leave that unchecked to bring up frame range and path options. Other options let you open the output directory after rendering to preview your progress, and generate a batch file based on your settings and the current file path.
The generated .bat file can be run without opening Blender. The addon is installed through Edit > Preferences > Add-on > Install, and is released under the MIT license. It supports Blender versions 2.83 through 3.1.