$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/vidarlo/.ssh/id_rsa):
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/vidarlo/.ssh/id_rsa.
Your public key has been saved in /home/vidarlo/.ssh/id_rsa.
The key fingerprint is:
SHA256:/jxfxiWiao0m7YG9MiHgXBFKoo7kJcgTOrPtAZNtpVg vidarlo@hannah.bitsex.no
The key's randomart image is:
+---[RSA 2048]----+
|..E o.           |
|=B.+.            |
|@==. .           |
|=O= .            |
|o=oo    S   . . .|
| .o.. .+   . o o |
|  .  ..o+o.   +  |
|      + =*o  o   |
|       B+ oo.    |
+----[SHA256]-----+
[~]$ 

$ ssh-copy-id user@host
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/vidarlo/.ssh/id_rsa.pub"
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
user@host's password: 

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'user@host'"
and check to make sure that only the key(s) you wanted were added.

0 5 * * * /usr/bin/scp "/path/to/backup" "user@remote:/path/to/store/backups"