When I put the mods on the 1.20.1 server and try to start it, it doesn't work and this error appears

[Solaris2024]

        at cpw.mods.modlauncher.Launcher.run(Launcher.java:108) ~[modlauncher-10.0.9.jar%2355!/:?] {}
        at cpw.mods.modlauncher.Launcher.main(Launcher.java:78) ~[modlauncher-10.0.9.jar%2355!/:?] {}
        at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:26) ~[modlauncher-10.0.9.jar%2355!/:?] {}
        at cpw.mods.modlauncher.BootstrapLaunchConsumer.accept(BootstrapLaunchConsumer.java:23) ~[modlauncher-10.0.9.jar%2355!/:?] {}
        at cpw.mods.bootstraplauncher.BootstrapLauncher.main(BootstrapLauncher.java:141) ~[bootstraplauncher-1.1.2.jar:?] {}

[Ugdhar]

Please read the FAQ (https://forums.minecraftforge.net/topic/125488-rules-and-frequently-asked-questions-faq/) and post your logs in full as described. Partial logs such as you shared in your post do not contain enough information to troubleshoot.