BetterEnd and BetterNether version not on Alternos

Hello, I would like to add the "BetterEnd" and "BetterNether" mods to my Alternos server, but I couldn't find any versions of these mods on the website, even though they exist on the CurseForge website.

Would it be possible to add them to Alternos, please?

PS: Only the "BetterEnd Reforked" mod is available on Alternos. Is this normal?

Quote from Adriel

It means the mods don't support your currently installed Minecraft version.

However, version 1.19.2, which is also the server version, is available on their websites =/. I'm not sure I understand how mod accessibility works on Alternos. Even if the mod has the server version, can't Alternos implement it on the site?

I just tested it, and indeed, the mods didn't have versions for "Forge". So I had to change the server version to "Fabric", and then the mods had compatible versions. I'll explain for future reference in case others haven't understood (like myself).

But wait, what is Forge, Fabric, and so on? What is the difference between them?