Here is a quick step-by-step guide to help you generate YouTube API key and use it with Video Importer WordPress plugin. Also, you can use this tutorial for any other project which requires YouTube API key on a WordPress website.
Step 1: Create a project with your Google Account
Go to https://developers.google.com/ and log with your Google Account or create an account, if necessary.
After logging in go to this link https://console.developers.google.com/project and click on the CREATE PROJECT button as shown in the image below.
Fill in whatever Project Name you want. For example: Video Importer.
Step 2: Enable YouTube data API
Click on the link called “YouTube Data API.” You can see it highlighted in the photo below, bottom right.
Now click on the “ENABLE” button.
Step 3: Generate a YouTube API key and connect it with your project
Next click on the blue “Go to Credentials” button to the right.
Choose the select option YouTube Data API v3 for the first select option and Web server (e.g. node js. Tomcat) for the second selection. Then choose Public data.
Now click the blue button, “What credentials do I need?.”
Almost done, wait for Google to create your new project and you should see the screen from which you can copy your API Key.
Then just copy/paste YouTube API key to Video Importer Settings in your WordPress website admin panel and save changes. YouTube video importing should work like charm right after.