HTML - firebase will not initialize in my website

Firebase will not initialize. I love being challenged, but after 2 1/2 days of not finding a fix, I need help!

Note: for some strange reason, config (in bold text below) is highlighted yellow in my text editor (I'm using brackets).

Here is some of my code:

<script src="/__/firebasejs/4.9.1/firebase-app.js"></script>
<script src="/__/firebasejs/4.9.1/firebase-auth.js"></script>
<script src="/__/firebasejs/4.9.1/firebase-database.js"></script>
<script src="/__/firebasejs/4.9.1/firebase-messaging.js"></script>
<meta name="viewport" content="width=device-width, initial-scale=1">

<title>My App Title</title>

<script src="/__/firebasejs/4.9.1/firebase.js"></script>
<script>
    // Initialize Firebase
    var **config** = {
        apiKey: "myapi",
        authDomain: "myappname.firebaseapp.com",
        databaseURL: "https://myappname.firebaseio.com",
        projectId: "myprojectid",
        storageBucket: "myappname.appspot.com",
        messagingSenderId: "mysenderid"
    };
        firebase.initializeApp(config);
</script>

Perhaps someone can tell me what I am doing wrong. I am brand new to coding, so I beg your pardon if this is an easy fix :) -lion