 After you have installed your key, it can be called any time by typing <code>Sys.getenv("CENSUS_API_KEY")</code> and can be
used in package functions by simply typing CENSUS_API_KEY If you do not have an <code>.Renviron</code> file, the function will create on for you.
If you already have an <code>.Renviron</code> file, the function will append the key to your existing file, while making a backup of your
original file for disaster recovery purposes.</p>
    </div>

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