Problem to access instance



I’m new to Scaleway, I’m using Win 10 OS.

I have followed the tutorial and start to create an instance with ubuntu Xenial OS.
After chose those OS required setting , i have generated RSA private and public key with 4096 bits via puttygen. After saved both private and public key in my local machine, I copied the content and paste for create a new SSH key.

After the instance creation complete i tried to use the private key with ssh via putty , but console returns ‘server refused our key’ . Anyone can help on this ? Thank you