How to degrade a font? basic CSS challenge

I’m stuck at the CSS basic challenge of how to degrade a font. I need to degrade the font to monospace in case Lobster is unavailable
this is how my code looks like:

h2 {
font-family: Lobster, monospace;}
I can’t figure out what I’m doing wrong here, please helpp

Did you comment out the <link> tag at the top?

Thanks for your reply
Yes, I did…