Kron PAM allows users to establish an SSH connection with a valid passphrase. To use an SSH Key, the Direct Credential Username and Private Key Passphrase need to be defined for the Device Group:
Navigate to Devices > Device Groups.
Click the device group and select the Properties option.
Click Edit then Next buttons.
Set the privileged target device username under Direct Credentials as a Username.
Set the SSH Key and its passphrase as Private Key and Private Key Passphrase.