I know this mod pack doesn't work well with a server in the past up the main reason for this is the ram and I know that's a problem with having a free server website but as long as it has 5GB ram it will work fine and I have seen my server getting 5 1/2Gb ram at times when I'm running big servers if this mod pack was added they should limit players to 5 or 10 and just keep the ram at 5 GB I don't know if this will ever be read but here are all the links.
MOD PACK LINK
valhelsia-3
server files for Valhelsia 3
Platform
Curseforge
Reqierments
1,235,971 Downloads
1.16.5
Description
"Valhelsia 3 offers something for every Minecraft player, no matter your play style. Builders will love the huge selection of gorgeous decorative blocks to expand the palette they can work with. Engineers and technical players have access to powerful automation and machinery. Adventurers will find plenty of structures to discover throughout the world, plentiful caves and underground dungeons, and even more when traveling into other dimensions. You might even find some rare artifacts!" ValhelsiaTeam-