SSH

Ssh-keygen on client

cp ~/<username>/.ssh/key.pub`` ssh-copy-id user@`

Paste in host

~/<username>/.ssh/authorized_keys
or
ssh-copy-id user@<IP>

windows ssh-copy-id

type $env:USERPROFILE\.ssh\id_rsa.pub | ssh {IP-ADDRESS-OR-FQDN} "cat >> .ssh/authorized_keys"

type $env:USERPROFILE\.ssh\id_rsa.pub | ssh pi4@rpi.lan "cat >> .ssh/authorized_keys"