I want to play with mods on my Minecraft server (1.12.2) but the default Forge versions are too low. The highest is 14.23.5.2847 but I need at least 14.23.5.2854. How can I select or upload higher versions? Here is a picture of the versions
Replace the server.jar via FTP.
Nitrado explains exactly how you can install each version of Forge.
https://wiki.nitrado.net/de/Eigenes_Minecraft_Modpack_hochladen#2._Manuelle_Installation_.28Eigene_Forge_Version_nutzen.29