If you want to import multiple videos from a playlist or search result you will need an API key. You can generate one by following the basic instructions below or you can take a look at the original Google documentation for more detailed steps.
You will firstly need a Google Account to be able to generate an API key.
You can now access the Google Developers Console. If you are not signed in you should be prompted to using your Google account. Here you can create a new project and fill in the form.
In the Project name field enter a value like My FooGallery. You can leave the Location field as its default value of No organization.
Click the Create button and wait for the new projects dashboard to be displayed. You should see a prompt informing you that you don’t have any APIs available to use yet. Click the Enable APIs and Services button displayed at the top of the page.
You should now be in the API Library. Simply enter YouTube into the search input and then select the YouTube Data API v3 from the results.
You will be redirected to the home page for the YouTube Data API v3, click the Enable button and wait for the operation to complete.
You will now be back on your projects Overview page. Click on the Credentials tab on the left of the screen. Then at the top of the Credentials page click on the Create Credentials button displayed at the top of the page. Select the API key option.
You should get a pop up titled API key created. From here you can copy your API key and optionally restrict its usage. For more information about restricting the usage please see the Securing an API key documentation.
Finally take your API key and enter it into either the prompt displayed during import or the FooGallery > Settings > Video > YouTube API Key option. You will be redirected to a new page. Scroll down to the section for YouTube and click on the YouTube Data API.