In Badminton Doubles, How Does the Serving Side Know Which Court to Serve From?

I’m learning badminton doubles and keep getting mixed up about the service court after a rally. I know the score matters, but I’m not clear on how the serving side’s position changes as points are won and lost.

Could someone explain the doubles service rotation with a simple example, such as what happens after the serving pair wins a point and then loses the next rally? I’d also like to understand which player serves when the score is even versus odd.