It keeps telling me to add the link element for the custom font inside the head


I'm new to the community. How is everyone? I'm getting this error when submitting:
Oops, try again. Inside the head element add the link element for the custom font.
This is what I have listed:

.jumbotron h1 {
    color: #fff;
    font-size: 48px;
    font-weight: bold;
    font-family: 'shift', sans-serif;

Any suggestions?

Font-family:'Shift', sans-serif

I figured it out. In index.html, I needed to add <link href="" rel="stylesheet"> as the first line under <header> before <link href="font.css" rel="stylesheet">.