We have a range of Minecraft modpacks available for automatic install from the LitePanel page.
Click Virtual/Dedicated Server (upper left) > Select 'Minecraft' > Click the dark bar on the left > Versions.
If you have no Minecraft software installed at all; Click the dark bar on the left, select Install Software > install Minecraft, then repeat the steps above.
Alternatively, you have full SFTP access to your server for uploading your own files and folders, including custom modpacks. Each modpack has its own installation instructions, but in general, the modpack files need to be unzipped directly into the /home/minecraft directory, so that the modpack's jar file and all of its folders are directly inside /home/minecraft.
This is especially useful for uploading custom mod packs or private packs.