Java is too new for this modpack
What causes it
The Java running this server is newer than the modpack can load, so its mods fail before the server starts.
How to fix it
Run the server with the Java version its Minecraft needs (1.18-1.20.4 packs need Java 17, 1.20.5+ needs Java 21), from adoptium.net.
Not sure this is your problem? Paste your log and Roastd will tell you which of these it actually matched, and what else it found.
Check your own log