The Seatalk HS network protocol is not compatible with regular Ethernet protocol. This means it is unable to connect to the DataHub.
If you also have a Seatalk NG connection available in your setup, such as on the back of a chart plotter, then you can add this to your NMEA2000 or N2K network if you use an adaptor cable.
Panbo has a great article that explains more about that here: https://panbo.com/finally-raymarine-seatalk-ng-to-nmea-2000-backbone-adapters/
With your device connected to an NMEA 2000 or N2K network, you can connect the DataHub to this N2K adaptor and use the onboard data source. If you need an N2K tee adaptor and M12 cable pack, these are available from PredictWind Shop.
Alternatively, if you have a Seatalk NG network already installed on your boat, you will need one of the white striped spur adaptor cables to change to the N2K connector and then connect it to the DataHub.
If you have a spare white Spur connector on your Seatalk NG bus, you can use this adaptor from Amazon to connect to the DataHub.