Annotating PDF files - SagerMakerExecutionRole can not assume role for sagemaker.amazonaws.com

I follow this tutorial : https://docs.aws.amazon.com/comprehend/latest/dg/cer-annotation-pdf.html#cer-annotation-pdf-set-up

At the step "Creating an annotation job", I get this error :

botocore.exceptions.ClientError: An error occurred (ValidationException) when calling the CreateLabelingJob operation: The role ARN arn:aws:iam::xxxxxxxxxxxx:role/xxxxxxxx-SageMakerExecutionRole-xxxxxxxxxxxxxx isn't valid. Make sure the role exists and that its trust relationship policy allows the action "sts:AssumeRole" for the service principal "sagemaker.amazonaws.com"

So, I went to IAM and check the trust relationships :

        {
            "Effect": "Allow",
            "Principal": {
                "Service": "sagemaker.amazonaws.com"
            },
            "Action": "sts:AssumeRole"
        }

Is that enough ?

I'm using the Ubuntu app under Windows 10.

I checked the version of boto3 :

# pip show boto3
Name: boto3
Version: 1.26.52
...

What can I do more ?

Thank you in advance !