Why is Linear gradient is not working for even though it works in the tutorial I am viewing

Question

Linear gradient is not working. The codes worked in a tutorial am watchin but it didnt work for me. I had to add a fallback. What is wrong with my code? Its an Angular project with scss styles and bootstrap.

html, body {
    background-color: $turquoise;
    background: linear-gradient(to top right, $turquoise, $blue);
}