Change a background colour on scoll

Hi all!

Hoping you guys can help: I'm currently trying to change the background colour of a section (specifically: [data-section-id="62037fbdae851a6c04ad1893"]) on my new website, but I'm having problems getting it to work. I've tried a multitude of tutorials and read through some topics on this forum, but I'm not getting anywhere unfortunately. I've tried the following: 

[data-section-id="my-section"] .section-background {
    background-image: linear-gradient(100deg,#3874ba,#edccc9) !important;
    background-size: 400% !important;
    text-fill-color: transparent;
    -webkit-text-fill-color: transparent;
    -webkit-animation: Gradient 10s ease infinite !important;
    -moz-animation: Gradient 10s ease infinite !important;
    animation: Gradient 10s ease infinite !important;
}

I've read through this thread and tried a few of the suggestions but still haven't got there.

My site url is: https://clementine-papaya-lfly.squarespace.com/ 
Access pass is: RylanCzuczman

Thanks for any help!