Error Accessing S3

I am trying to connect. I have my keys in and zone s3-us-east-2.amazonaws.com

I get this message:

Warning: S3::listBuckets(): [InvalidRequest] The authorization mechanism you have provided is not supported. Please use AWS4-HMAC-SHA256. in /home/[name redacted for this post]/public_html/wp-content/plugins/woo-product-download-from-amazon-s3/includes/S3.php on line 373