How do I teach my puppy to play alone?

I have an 11 week old lab puppy who really struggles to play by himself. I have tried ignoring his whining and barking at me to play with him, but then he just goes and rings the bell to go outside because he knows I will get up and take him. How do I get him to play by himself and not need my attention every waking second? It’s truly exhausting and I feel like I get absolutely nothing done since I’ve gotten him