Choose a Google font
For simplicity, let's choose a Google font, let's say Merienda
Add the code in the Code injection
We get the code, not add it in the Code injection header:
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
<link href="https://fonts.googleapis.com/css2?family=Merienda:wght@400;500;600;700;800&display=swap" rel="stylesheet">
Set the heading font name
<style>body{--font-headings: 'Merienda';}</style>