How to SSH into RancherOS instances created in DigitalOcean via the UI

Hello ,

I have created a host using DigitalOcean via Ranche UI.
Now i am trying to access to host via ssh after download the machine config.
I placed the all the cert n key files in one unix host:

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root@nodejs-machine:~/Neo4jHost# ssh -i id_rsa root@
You are required to change your password immediately (root enforced)
Welcome to Ubuntu 16.04.4 LTS (GNU/Linux 4.4.0-127-generic x86_64)

** System restart required ***
Last login: Mon Jul 23 06:53:16 2018 from ipaddress
Changing password for root.
(current) UNIX password:

==

It is asking for Unix password, i am not sure about the password.

Could someone help me on this.

Regards,
Vijay.

I am able to login with Id_rsa key
Thank you