serverless-apigwy-binary | Serverless framework plugin to configure Binary responses | REST library

I'm trying to upload images to an S3 bucket using the serverless framework. When I call the endpoint after deploy the code fails with an Access Denied error. What am I doing wrong?

The error using 'serverless logs -f fileDownload':

I'm writing an API for internal use, and for the first time I'm using the serverless framework. I'm writing a Lambda function in Node.js, and using the AWS API Gateway to connect to it.

In some cases I want to return a custom error message, and I'm trying to write a function that would allow me to do that. Right now, any time the Lambda process fails, I get a standard message from the API. In the code, if I try to kill the process using process.exit(1), I get a generic error, even if I've already returned an error using callback():

I have a serverless app which uploads files to s3 (via POST request) and serves them (via GET request)

I am using serverless-apigw-binary and serverless-apigwy-binary plugins to allow me to return binary data in the form of an image. In order to allow the URL to work with browsers, I have to set the binary types to */*.

In order to upload an image the POST endpoint takes a body like { "base64": "..." }. However with this configuration the entire body is coming through as a base64 encoded string. How can I prevent the request body with application/json being transformed?

See serverless.yml below: