Hi there.
Seems you have created a remote with name "rclone config". Probably not what you intended..? Did you see the example "session" ("This will guide you through an interactive setup process:") at https://rclone.org/dropbox/? Try to follow that.
Then, you need to add : suffix when referring to the remote name. So if you have a remote called "dropbox" (of type "dropbox", it can be a bit confusing when writing about remotes with same name as the backend/storage-system type) you would have to do:
rclone ls dropbox:
rclone mount dropbox: /home/pi/dropbox
etc..