This code needs to be added to the head of your site, it can either be your home page or all pages:

<script type="application/ld+json">
      "@context" : "",
      "@type" : "WebSite",
      "name" : "The name you want",
        "alternateName": ["The name you want", "an alternate name"],
      "url" : ""

Be sure to replace the following "The name you want" <-make sure you keep the "

Also change AlternativeName ["The name you want", "an alternate name"] again make sure that you just replace the words and not the " ; or ] portions of the code

url - replace yourwebsite with your website (keep the www. and only change the .com if you need it but again keep the "

After you install this on your site you can test it by going to a Schema Validator