Not sure who is in charge of setting up cards for the online Jigoku but the first elemental pack is already on fiveringsdb for deck construction but you cannot import it into Jigoku because all the cards are not there.

Try using their page to report the problem. They’re not affiliated with FFG in any way, and we don’t know if/how often they read this forums so there’s really not better way to contact them than to use their own page.

That being said, they normally don’t put up cards until the packs are out.

They mostly don't look at these forums, it is better to ask in the L5R Discord. However, they very much know that the cards exist and are working on them.

Cards have to be coded by a volunteer team. They have been working diligently (imagine trying to code Mirror's Gaze to work as intended!) to get everything ready for release date. That said, cards are not fully implemented on jigoku until their official release date. If you do have some previewed cards show up on there, you'll have to play them manually anyways.