需要自定义JavaScript从数据层的项目数组中获取价格乘以数量的总和

当前的GTM数据层没有显示签出总值，我需要从数据层的items数组中获取该值。

`event: "checkout",
  gtm: {uniqueEventId: 243, start: 1675793207075},
  ecommerce: {
    checkout: {
      actionField: {step: 2},
      products: [
        {
          id: "80509",
          name: "Delightly: Inner Peace Kit",
          category: "Delightly Quick Ship Kits",
          variant: "80509",
          price: 109.95,
          quantity: 1
        },
        {
          id: "80396",
          name: "Delite by Delightly: Just Breathe Kit",
          category: "Delite by Delightly",
          variant: "80396",
          price: 44.95,
          quantity: 1`

我需要价格的总和乘以数组中的数量