I am able to connect my android mobile phone to my Debian system using MTP protocol. I can access the files (read and write) there in the file manager. In SalixOS+Mate, I installed files kiomtp and libmtp and many commands are available, but I do not know how to see my android device in the file manager:
You don't see it in the file manager. You have to connect to it using the MTP protocol. You can install gmtp for a simple GUI client. Or you can install mtpfs if you actually want to have (an emulated through fuse) mountpoint.