Problem with auth in AWS

Hi! I am using Bamboo to send some emails with the SES Adapter (the email service from AWS).
To make authentication for the service the lib ex_aws is used, I use the default configuration for that, the environment variables for access_id and secret. But when I try to send an email I receive:

{:error,
 %Bamboo.ApiError{
   message: "{:http_error, 403, %{body: \"<ErrorResponse xmlns=\\\"http://ses.amazonaws.com/doc/2010-12-01/\\\">\\n  <Error>\\n    <Type>Sender</Type>\\n    <Code>SignatureDoesNotMatch</Code>\\n    <Message>The request signature we calculated does not match the signature you provided. Check your AWS Secret Access Key and signing method. Consult the service documentation for details.\\n\\nThe Canonical String for this request should have been\\n'POST\\n/\\n\\ncontent-encoding:identity\\ncontent-type:application/x-www-form-urlencoded\\nhost:email.us-east-1.amazonaws.com\\nx-amz-date:20210414T180110Z\\n\\ncontent-encoding;content-type;host;x-amz-date\\n54d5034558ac42946873e79cc6419df4b7a69a32f7d5ea0882407624ce5e8eae'\\n\\nThe String-to-Sign should have been\\n'AWS4-HMAC-SHA256\\n20210414T180110Z\\n20210414/us-east-1/ses/aws4_request\\nbc72f280b3b6ac7682921ce7b6f8582ed3382be4d3dd93bf6ca0da7186378c61'\\n</Message>\\n  </Error>\\n  <RequestId>fdfa8be6-39f9-4482-b0d5-442b6471de0c</RequestId>\\n</ErrorResponse>\\n\", headers: [{\"Date\", \"Wed, 14 Apr 2021 18:01:11 GMT\"}, {\"Content-Type\", \"text/xml\"}, {\"Content-Length\", \"919\"}, {\"Connection\", \"keep-alive\"}, {\"x-amzn-RequestId\", \"fdfa8be6-39f9-4482-b0d5-442b6471de0c\"}], status_code: 403}}"
 }}

Note: When I use temp credentials from AWS the email is sent, but its temporary credentials, won’t long for production use.

Somebody who uses AWS’s services in Elixir had faced this?
Thanks in advance.