To set up ssh password-free login to the remote server

In this arrangement the server IP address is 39.96.46.85, the port number is 22, the user is root.

Step 01: After entering the command, press Enter three times.

step 02: The key is sent to the remote server.

step 03: Log on to the server, copy the key to the cloud server settings.

step 04: Configuring login information.

step 05: connection test.

Reference: https://www.cnblogs.com/bingoli/p/10567734.html