Alpakka SQS doesn’t have specific support for Proxies.
It should be possible though to use Akka HTTP’s proxy support and put an amended Akka HTTP client in place as this example does with using Netty.
Alpakka SQS uses aws-spi-akka-http to implement the SdkAsyncHttpClient interface. In that library would be a great place to add preconfigured proxy support.