You need to import a key pair in either of the following scenarios:
If the public key of the existing key pair is stored by clicking Save public key on PuTTY Key Generator, the public key cannot be imported to the management console.
If you want to use this existing key pair for remote login, see Why Does a Key Pair Created Using puttygen.exe Fail to Be Imported on the Management Console?
Make sure that the file to be imported is a public key file.
After the public key is imported, you can change its name.