I've been trying to make a modded server for me and my mates to play on but every time I install a server from the forge installer it keeps creating a vanilla Minecraft. I must say that some of my mods work like Voxel Mod and JEI Mod but I can't place any modded item in the world, like items from Thuamcraft or Pam's HavestCraft. I also have Biomes O Plenty Mod and they don't appear in the world.
I'm using the Forge 1.12.2 - 14.23.5.2838.
I hope there is a solution to this or the forge server only allows small mods.