Well this is how i did it on my server (wich is rented).
first i downloaded DB Browser for SQlite wich you will need to add new records and read the Game_DB
After that i went in my own singleplayer session and visited the three forges , so they would pop up in my Game.DB from conan exiles in the steam game folder . they got certain id numbers wich i used to put in my Server game.DB after that the forges are there and working . and you wont loose any progress or saves from your server ,neither will the players playing on that . i can explain it step by step but i would be typing a freaking book
. if you know what to do its just a matter of copying the id numbers from SP to you Server Data.DB thats it .assuming you already added the records .
So if you wiped your server to restart it a while back, this is what happens. You loose those special crafting location. Bat altar, Black ice forge, Obsidian forge and Chaos Mouth altar. They have a functional fix for that now, to prevent the loss of those, by using their ServerCleanup.bat file, located in: