关于 Git sshkey 的问题？

vagrant@homestead:~/code/Laravel$ git push -u origin master
The authenticity of host 'github.com (13.250.177.223)' can't be established.
RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
Are you sure you want to continue connecting (yes/no)?
Host key verification failed.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

每次 git push -u origin master就报如下错误，但是ssh key我也是按照教程来的，感觉没错啊，求助各位大神！