How/what to add for Schema Mark-Up to display star rating on Google listing?

Hello,

I am trying to add the schema mark-up to this website that I have created...

For the artist listings pages (like this page), we want to have our 5-star rating display on Google.

I've done as much research as I can but keep getting different information as to how we get this working. Do we need to add the schema mark-up to the actual stars (near the footer of each site which links to our testimonials page) or do we just add some schema code within the frontend code somewhere?

Initially, the code looked like this:

<script type="application/ld+json">
{
  "@context": "http://schema.org/",
  "@type": "Product",
  "name": "Wedding Bands",
  "image": "https://www.tailored-entertainment.com/wedding-bands",
  "description": "Professional UK-based live bands for hire.",
  "brand": "MY COMPANY NAME",
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "5",
    "bestRating": "5",
    "worstRating": "1",
    "ratingCount": "1989"
  }
}
</script>

Any help would be much appreciated.

Thank you very much,

SM