curl --request GET \
  --url https://api.sprucecollective.co.uk/merch/products/slug/{slug}

{
  "active": true,
  "asset_url": "<string>",
  "collection_id": "<string>",
  "color": "<string>",
  "created_at": "<string>",
  "id": "<string>",
  "image_url": "<string>",
  "item_id": "<string>",
  "locale_id": "<string>",
  "metadata": {},
  "name": "<string>",
  "price_gbp": 123,
  "site_id": "<string>",
  "sizing": "<string>",
  "sku": "<string>",
  "slug": "<string>",
  "updated_at": "<string>"
}