I need In App Purchase | In App Purchase 2 project sample

i need In App Purchase | In App Purchase 2 project sample in ionic vue.

i get error:
{code: -2, message: “Billing cannot be initialized”, errorCode: -2}

A code snippet of what you’ve tried would help people help you.

const iap = await InAppPurchase;

  iap

    .getProducts(["1212"])

    .then((products) => {

      console.log(products);

    })

    .catch((err) => {

      console.log(err);

    });

Unable to read manifest file:java.io.FileNotFoundException: www/manifest.json
Error: Billing cannot be initialized
restorePurchases() {“code”:-2,“message”:“Billing cannot be initialized”,“errorCode”:-2}