Problem running circleCI


I have these error while running the CircleCi V2 build

Cloning into ‘.’…
Warning: Permanently added the RSA host key for IP address ‘’ to the list of known hosts.

Permission denied (publickey).

fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
Exited with code 128

there is the content of .config.yml

version: 2
- image: circleci/ruby:2.3.4
- checkout
- run: echo “hello world”

I have already create a deploy key in github