Does anybody have any experience building interfaces for Amazon AWS services based on the classes included with...

Does anybody have any experience building interfaces for Amazon AWS services based on the classes included with Delphi (Tokyo 10.2.1 Ent)? I've been going through Pawel's CodeRage X video and I find the part around authentication quite unclear. The Delphi classes use V 2 of the auth services by default, while virtually all of them use V 4 (and have for a while). The fields it uses don't seem to align with those in Amazon's docs. I need to interface with one of the less-used services (Polly), and the only examples I've found are for S3 and what Pawel discusses. His presentation is great, but I've replayed the 2nd half several times and there's stuff that just isn't connecting for me.