Using keys is much safer than using passwords, which is why Linux storage providers give you keys to log in via SSH—if you have a virtual server—so you can log in securely.
This guide is for using the Putty software, but the settings are similar in all software.
1. First, install putty: download link
2. After installation, open the software and the following screen will appear:
3. On the left side there is a menu: Connection -> SSH -> Auth -> Click on the Browse button and select the key file that we sent you by email.
4. After selecting the file, return to the initial screen. In the left menu under the Session tab, enter the username (root) and your server's IP address in the Host name field. For example:
5. You can save the settings for later use.
6. After connecting, a screen will appear asking for your permission to save the address in the software cache for future use.
Confirm the message and you will be able to connect to your VPS server.
Good luck!