The first thing you need is to head to to create your first project. In case you already have a project in place, head to the credentials section.
Create a project
In https://console.cloud.google.com/apis/dashboard?pli=1 choose create a new project, set a name and hot continue.

Create a credential
Once you have your project in place is time to create a new API key that will be the one used in the plugin. For that go to Create Credentials -> Api Key

Add security
Once you create the api key it’s time to protect it so it can be only used from your website. If you have a staging site don’t forget to also add that domain.
In this step you can laso copy and paste the key to the plugin settings page.

When you click restrict key a new window will appear where you need to fill some details as explained below:
- Name: Something that will let you identify the api key
- Restrictions: The easiest is to restrict by website, but you can also use IP address for example
- Web site: Here you need to add as many items as needed, one for each website where you plan to use the plugin
Once you fill the details hit Save and the key will be protected.

Verify your account and add billing
Is this is your first project Google will ask you to add a credit card in order to verify your account. They will give you 300USD worth of credits each month for free, which is more than enough for almost every project. If you exceed that they will charge based on requests.