Attachments: Up to 2 attachments (including images) can be used with a maximum of 512.0 KiB each and 1.0 MiB total.
It is not possible to create a bucket for you. RTH provides a signed URL, and it might be possible to copy data to your S3 bucket as suggested in this post.
Tick history raw data extract is not sort in timestamp
TRTH REST C# API on .NET Standard?
Tick History Relative Query
Invalid EndOfStream c# gzip
Retrieve tick history of different instruments for different time range