dokku: Error uploading to git remote

Hi I have succssfully deployed Dokku, but I can’t seem to deploy using the git remote dokku dokku@domain.... command. It either return a Enter password field or it tells me the git repository doesn’t have the rights to do so.

I tried to cat id_rsa.pub | ssh... but what should I input for ssh. Because if I were to do a ssh dokku@<hostname> it would fail as well because there isn’t such a user. I am running on an Azure Ubuntu VM.

Please advise.