No Transaction ID being pushed in the datalayer

{
  event: "conversion",
  gtm: {uniqueEventId: 6, start: 1701338992403},
  pagePostType: "page",
  pagePostType2: "single-page",
  pagePostAuthorID: 197619728,
  pagePostAuthor: "cookiesandclicks",
  postID: 27029,
  cartContent: {
    totals: {
      applied_coupons: ["2vth542x"],
      discount_total: 32.24,
      subtotal: "32.9",
      total: "0.66"
    },
    items: [
      {
        id: "3052503825403",
        internal_id: 23717,
        name: "Bourjois Contour Clubbing Waterproof Oogpotlood - 54 U" +
              "ltra Black",
        sku: "3052503825403",
        category: "Make-Up/Oog make-up/Oogpotlood",
        price: 7.5,
        stocklevel: 2,
        quantity: 2
      },
      {
        id: "8002110383709",
        internal_id: 2194,
        name: "Neutrogena Ongeparfumeerd Handcrème",
        sku: "8002110383709",
        category: "Verzorging/Handcrème",
        price: 8.95,
        stocklevel: 3,
        quantity: 2
      },
      {
        id: "3600530883042",
        internal_id: 43987,
        name: "Maybelline Duo Liner Eyeliner - Zwart",
        sku: "3600530883042",
        category: "Make-Up/Oog make-up/Eyeliner",
        price: 6.95,
        stocklevel: 15,
        quantity: "1"
      }
    ]
  },
  ecomm_pagetype: "other",
  eventModel: {transaction_id: ""}
}

Hello, in the purchase event datalayer the transaction ID is being left blank and I cannot find it anywhere else in the datalayer. How can I fix this?

The page I need help with: [log in to see the link]