Many AWS services are protected by TLS/SSL rather than Amazon Identity and Access Management (IAM). You can proxy those services the same way you proxy any HTTPS service from Edge. For the AWS services you're using, see the AWS documentation for any message requirements.
In Edge, create and implement your API proxies any way you like, whether you use the standard configuration (as shown in the Build your first API proxy), use a standard configuration that includes Node.js, or uses Node.js exclusively.
For information on creating API proxies to IAM-protected services, see Create API proxies to IAM-protected services.