Smartapps: http post to upload files to S3 buckets

All - Does anyone have an example code on how to send data to S3 buckets from Smartapps? The document provided with Smartthings is very rudimentary and it doesn’t cover the authentication of AWS credentials. Any help on this topic will be much appreciated. This is for a project that connects the Spruce Moisture Sensor to S3 so that the data can be used by a Raspberry pi based Sprinkler.