Install a Fabric Snapshot 1.15-pre4 server through the Control Panel (Servers → Select your server → Game servers → Add Game Server → Fabric Snapshot 1.15-pre4)
Fantastic service for a great price. Very easy to download packs onto the server. My only issues and complaints are it doesn't have every pack available and the FTP process is tedious. I also can't see what version the packs they have downloaded on the site are and if they correspond with version info.