You can simply update the server app by using git & you may need to run some commands after updating the source code, please follow the below steps.
You can get the exact changes with your current version by comparing the source code by using git.
by following the below video link, you can get the difference what exactly changed with your current version with our updated demo source code.
After updated the source code in the server side, you need to run the below commands.
That's it, you have updated the backend app now.