Use it
SCP
Stock scp to the Host name from az ssh config.
az ssh config ~friendscp ./file friend:scp ./file friend:~/inbox/The Host line is the point with the ~ removed. User and Port follow the stanza. Both install and log in. They add you, you az mesh accept them, you send the file.
scp -6 to the overlay address is the same path when you already have it from az peer add or az ssh.