django - How to connect to server with only username and public ssh key? -

i want utilize batch file connect amazon server using ssh private or public key.

i have tried

open sftp://user:password@example.com/ -hostkey="ssh-rsa 2048 xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx"

psftp fred@server.example.com

in script not able connect server. getting error.

disconnected no supported authentication methods available (server sent publickey)

i able connect putty. want batch file connect server , restart django project in that.

if able connect need go path of django project , run command

manage.py runserver

ssh -i privatekey.pem username@server.example.com

django ssh amazon-ec2 winscp

Four