On Linux or OSX you can unzip ngrok from a terminal with the following command. On Windows, just double click ngrok.zip.
Running this command will add your authtoken to your ngrok.yml file. Connecting an account will list your open tunnels in the dashboard, give you longer tunnel timeouts, and more. Visit the dashboard to get your auth token.
./ngrok authtoken <your_auth_token>
Try running it from the command line:
./ngrok http 80