The LaodMaxValues class accepts --region and --table-name as a parameter, or you can pass in environment variables for the AWS_DEFAULT_REGION as is done with docker below.
docker build -t print-distinct-pks .
docker run --rm -it
-e AWS_ACCESS_KEY_ID=$AWS_ACCESS_KEY_ID
-e AWS_SECRET_ACCESS_KEY=$AWS_SECRET_ACCESS_KEY
-e AWS_DEFAULT_REGION=$AWS_DEFAULT_REGION
-e DYNAMODB_TABLE_NAME=my-table-name
print-distinct-pks
docker rmi -f print-distinct-pks