Download now. The server is constantly checking for updates and will update if no one is on the server. The download is now automatically the latest and greatest. Extract location: c:/Program Files (x86)/Steam/steamapps/common/Valheim/
It should auto route to existing stacks in nearby containers with a notification.
Ignore this in general unless you know what "Advanced" means. If you want to know more ask someone about it or read up on ValheimPlus AEM and ABM.
Here's the guide to using