Your puppy is a crybaby. They whine and whine and whine until you think you'll lose your mind. Nothing you do seems to stop the crying. Your pup is well-fed, has a comfy place to sleep, and goes outside regularly. You can't figure out what is making them whine all the time. Training your puppy to not whine requires understanding what is prompting the behavior.
Whining, like barking, is a way for your puppy to communicate with you. Often, puppies whine instinctively when they are left alone. Being left alone in the wild is incredibly dangerous for young pups, so your dog is trying to alert their pack that they are in danger. Puppies also whine because they are over-excited or because they have learned whining gets them the attention they want. You may have accidentally taught your pup to whine by rewarding the behavior with love, food, or whatever else your puppy wants.
Training your puppy not to whine will require a strong commitment from you and from anyone else your puppy interacts with. For your puppy to learn that whining doesn't get rewards, everyone needs to be on the same page and decide to react to whining the same way. For these methods, you will also need a room you can safely leave your puppy alone in, or a crate, and some training treats.