You can download pro editions from https://plus.seafile.com/d/6e5297246c/?p=/pro.

If you are deploying Seafile Pro with Docker, type docker login docker.seadrive.org, then input username seafile, password zjkmid6rQibdZ=uJMuWS.

Note, from version 12.0, the docker image is hosted on DockerHub and does not need a password to access.