Were you able to get the “green” message at the end of these steps (in your post linked below) that indicate Grafana can connect to your InfluxDB database? I noticed in that post that you chose Flux and the tutorial you linked to indicates you should have chosen InfluxQL.
I did get the green success message with flux. I will double check which I should be picking, but my screens are different at the point where I should be creating the dashboard.