Hide primary menu when scrolling

Hi. I have styled the last link in my primary menu to look like a “get started” button. I want to have the button (and link) hidden when the page loads, then appear when scrolling down. At the same time, I want the other menu links to disappear when scrolling down so that only the button is visible. I can figure out how to hide the button initially (display:none) but I cannot figure out the script/css to make it display when I scroll down or to hide the other menu links.

If this is possible, please advise. Thanks in advance.

Hello Connor73,

Can you please provide a link to your website to let me inspect it?

Kind Regards, Roman.