To run this on your own server, you will need to do the following:

• Create an app on the google cloud console
• Enable google vision api
• Step 1: Under "API and Services", click enable api
• Step 2: Choose google vision api
• Step 3: Create an API key so your app can call the vision api

Then, look at the comments in index.html file, should be self explanatory.

Simply deploy the index.html file to your web server. The live version can be see at https://env3d.github.io/oauth-vision-api-tutorial/