The easy way: upload a world with its packs
- In Minecraft, open your world and turn on your add-ons in it.
- Export the world as a .mcworld file.
- Rename the file to .zip and upload it to the worlds folder with the panel's file manager.
- Extract the archive in the panel to get the world folder, with no folder in between.
- Put that folder's exact name in level-name, in server.properties.
- Restart the server.
An exported world can hold its behavior and resource packs, with the list of the ones turned on: the server loads them with the world. If an add-on needs experimental features, turn them on in the world before exporting it.
Add a pack to an existing world
A .mcpack file is a zip archive. Rename it to .zip, upload it to behavior_packs or resource_packs depending on its type, then extract it in the panel: the manifest.json file must sit directly in the folder you get.
In that manifest.json, note the uuid and version from the header section. Add them, as pack_id and version, to the world_behavior_packs.json or world_resource_packs.json file at the root of the world folder, depending on the pack's type, then restart.
Require the textures
To make players download and use your world's resource packs, set texturepack-required=true in server.properties with the panel's file editor.