on-prem sybase to aws aurora

I want to migrate from on-Prem Sybase to AWS Aurora Postgres database. I came across tools like AWS SCT and AWS DMS, but I am not sure , if the source Sybase database should be in AWS cloud as a pre-requisite for the AWS tools to initiate the migration. What are the other options we have in case we want to migrate from On-Prem Sybase to AWS Aurora Postgres database.