Upload the fasta version of each and use them as Custom Genomes “from the history”. You can also promote any fasta to a Custom Build to generate a “database” that can be assigned to datasets (some tools may require that metadata assignment).
There is much prior Q&A about using Galaxy this way that covers the how-to FAQs plus details and other troubleshooting. I added a few tags to your post to help in finding those.
The usegalaxy.eu administrators may write back, if they decide to add the genomes directly. There is a hackathon going on today, so replies may be delayed. But you don’t need to wait – using a custom genome/build is accessible to everyone at all usegalaxy.* servers and most other public Galaxy servers.