About AWS4 Signing
"When you send API requests to AWS, you sign the requests so that AWS can identify who sent them. You sign requests with your AWS access key, which consists of an access key ID and secret access key. Some requests don’t need to be signed, including anonymous requests to Amazon Simple Storage Service (Amazon S3) and some API operations in AWS Security Token Service (AWS STS) such as
Bubble.io does not have a current solution, so Fliplist built a plugin based on the blog post & code created by the Wimpy Programmer.
We went with the server side Crypto-JS solution at the bottom of the page.
BLOG POST HERE ( thank Drew)