Sagemaker instace is not able to run again. is there a way to run it or at least access the EBS

SageMaker Instances are not accessible as a normal EC2 Instance, as they are managed by AWS. You cannot attach or mount the EBS volumes from another Instance. The best way to protect against these situations is to use S3 as a backup medium, this blog post helps you on this technique : https://aws.amazon.com/fr/blogs/machine-learning/migrate-your-work-to-amazon-sagemaker-notebook-instance-with-amazon-linux-2/