Change Minecraft Server as Mod Server?

I wanted to create a Pixelmon Server so change my Vanilla Server to Mod Server but no matter what I do the server stays on either 1.14.4 or Spigot 1.14.4 and I need Minecraft 1.12.2 with Forge.

I didn't find anything on Google because the only thing that was with winscp is at Nitradopedia and my server is not properly paid for on Nitrado.

It would be really nice if someone could help me (little info on the side I will not write you my login data or something) But I can say that I use multicraft and Winscp.

~ Luna

Search Youtube for "Set Up Nitrado Forge"

Then what you are looking for will come

You have to set up the server again and then change the version

My server is not on Nitrado I wrote

Then why are you looking at Nitrado Pedia? Where did you host your server?