It took me a few days, but it was worth it. I wrote all the required unit tests for my backend APIs. To be honest, I should have done it from the start instead of using Postman to test the endpoints. But now it is done.
These last few days completely changed the way I think about writing backend code. Use TDD. You won't regret it. It is not a waste of time.
PS: I am using Japa + Chai, but you can use Jest if you are more familiar with it.