Step 1: log into your Google account then go to the website: https://console.developers.google.com/projectselector/apis/credentials
Step 2: Click on the blue button “Create a project”.
Step 3: click on the button “CREATE”. Wait a few seconds then you see the screen:
Click on the blue button “Create credentials”, you will see 4 options to choose.
Step 4: Click on the option: “OAuth client ID”, now you will see the screen:
Click on the blue button “Configure consent screen”, then fill the field: “Product name shown to users”
Now, click on the button Save at bottom of this page.
Step 5: Select Application type
Step 6: Click on the button Create, you can see your client ID and your client secret
Done, now you can use these informations to configure your code.