Deployment failed on vultr server using circleci

deployment:
push_to_server:
branch: master
commands:
- rsync -avz _site/ user@xyz.com:/var/www/
This is my circle.yml file i got result as no test.I want to deploy my git repo on vultr server so how i can achieve that? I want to debug my build on circleci/build server using ssh so how i can do that?
I tried to ssh build server using ssh -p 64626 ubuntu@54.90.249.79 also using same ssh public key that use for github but got permission denied error.Please help me on this issue.