Zend certified PHP/Magento developer

no supported authentication methods available (server sent publickey) Putty Windows

Good evening everyone ,
I created an instance on my OvhCloud host,
I followed the whole process from key generation to configuration of the instance detailed on this link: https://docs.ovh.com/fr/public-cloud/premiers-pas-instance-public-cloud/
Now I use Putty to connect to this instance created with the private key generated on PuttyGen.
But I can’t access my instance I get this error (no supported authentication methods available (server sent publickey)

I would like to know where the problem lies ???