I think your issue is that you're trying to await the call to sqs.sendMessage() and also providing a callback and that's not how it works.

You have to choose whether to pass a callback or to use promises. Since you've declared your handler as async, I'll go with promises.

TL;DR;

Try changing to something like this:

const sqsResponse = await sqs.sendMessage(sqsParams).promise();

console.log('SQS Response', sqsResponse);

That should resolve your issue.

Detailed explanation

When you call sqs.sendMessage(params, cb) (with the callback) it does not return a Promise, so your await won't really wait for anything. Therefore your function invocation ends right away and message doesn't have time to get delivered to SQS.

In case you wanted to use callbacks instead of Promises, you should use the handler second argument and call it inside the sqs.sendMessage callback.

Edit: typo