Build SageMaker container get started has missing S3 bucket

Going through the Get Started: Use Amazon SageMaker Containers to Run a Python Script page:
https://docs.aws.amazon.com/sagemaker/latest/dg/build-container-to-train-script-get-started.html

I think I made a mistake and deleted the S3 bucket that it created. Now it can't find it and I can't create a bucket with that name anymore. I tried creating a brand new Notebook and starting over but it still looks for that same S3 bucket.

How can I reset things to use a new S3 bucket or get the S3 bucket back?

Any help appreciated.