Considering reading https://www.digitalocean.com/community/tutorials/how-to-use-the-dokku-one-click-install-image-to-deploy-your-app I created a Droplet as described, then I redirected my domain to the Ip adress of the droplet, checked virtual host naming and pasted my public key.

Right after I cd'ed in my local directory and then

git init
echo vendor > .gitignore
git add .
git remote add remote_name dokku@your_domain.com:name_to_give_your_app
git push remote_name master

Result:

error: src refspec master does not match any.
error: failed to push some refs to 'dokku@domain.com:remote_name'

What did I miss?