We currently do not have sufficient c7a.xlarge capacity in the Availability Zone you requested (us-east-1b). Our system will be working on provisioning additional capacity. You can currently get c7a.xlarge capacity by not specifying an Availability Zone in your request or choosing us-east-1a, us-east-1c, us-east-1d, us-east-1f.

InsufficientInstanceCapacity: We currently do not have sufficient c7a.xlarge capacity in the Availability Zone you requested (us-east-1b). Our system will be working on provisioning additional capacity. You can currently get c7a.xlarge capacity by not specifying an Availability Zone in your request or choosing us-east-1a, us-east-1c, us-east-1d, us-east-1f.