SSH (Secure shell) is a tool that allows you to remotely control another computer from your own.

On the client, you should run the following command:

ssh-keyring

This command is going to generate two files in your ~/.ssh directory: id_ed25519.pub and id_ed25519. This is your public/private key pair.

Generating public/private ed25519 key pair.
Enter file in which to save the key (/home/user/.ssh/id_ed25519):
Enter passphrase for "id_ed25519" (empty for no passphrase):
Enter same passphrase again:

After it's done, you should see something like this:

Your identification has been saved in id_ed25519
Your public key has been saved in id_ed25519.pub
The key fingerprint is:
SHA256:A9XgEuUAq5PT+TydcezaAL2iZCAWkOZLSsYjnR1rct4 user@client
The key's randomart image is:
+--[ED25519 256]--+
|..  ..o.+o       |
|o.  .. *  .      |
|+o o.oo o        |
|.B=+=. + .       |
|B.O=o.. S o      |
|oo +.oEo B       |
|    o = = .      |
|   o . o +       |
|    .   . .      |
+----[SHA256]-----+

• https://man.openbsd.org/ssh-keygen.1