Adding a subheading to my product page

Site URL: https://viridianartist.com/buy-art-thursday

Hi! I am trying to add some information to the top of my product page.

I want to show that if products are purchased on that page, buyers will receive a  10% discount.

I do not want to use an "announcement bar", because I don't want this text to be seen on every page.

I just want it on one specific page. Is it possible to do this by adding some kind of code?

Thanks so much in advance, if this is possible please let me know.

Add to Design > Custom CSS

div#productList:before {
    content: "add your text here";
    display: block;
    text-align: center;
    font-size: 20px;
}