Google provides a number of useful tools such as the ability to embed interactive maps into a web page or the ability to query elevation data based on GPS coordinates. Often, the use of each Google tool requires that a "query" or "call" is made to an Application Programming Interface (API) for that Google tool. This page will describe the steps to setting up a Google account and enabling one or more of those tools for your personal use.
Chances are, you already have a google account. If you use Gmail, you already have an account. If not, navigate to Google and set up an account.
The remaining steps will walk you through the process of setting up your Google account with access to the elevation API. You may also simply follow Google's instruction for setting up an Elevation API service.
To use a Google API, you must first create a "Project". A Google "Project" is used to manage any Google service (such as elevation data) that you choose to use.
In order to use any of these Google services, you must enable billing and provide a credit card. Don't worry, as long as you don't go over the monthly quota for that service, you won't be billed. You can set up a quota so that your usage never goes over the free threshold.
Navigate to your project's page then enable the Maps Elevation API.
At this point you should be able to get your Google Elevation API Key for use in tools like Virtual Litchi Mission or these Litchi Utilities. Navigate to the Google Maps Console.
The key obtained in the previous step may be used in Virtual Litchi Mission or these Litchi Utilities to provide access to your own elevation data. Now that you have created your own API key, you may wish to set up a quota so that you never exceed the free usage limit.