After logging in with metamask, I want to authorize according to whether the user has the Nft I want in their wallet (or rather, we can say according to the contract address of the token I want). But I return if else in the code. If the balance is greater than 1, I want to authorize it. "window.parent.postMessage" is not coming.

Connect metamask

  <button class="rounded shadow-md bg-white px-4 py-2 mx-2 leading-8" @click="connectMetamask">
    <img src="./../assets/images/metamask.svg"
    class="inline-block mr-2" width="24" height="24" alt="Metamask">
    Connect Metamask
  </button>
</template>
<script>
import Web3 from 'web3';

export default {
  name: 'ConnectMetamask',

  methods: {
    async connectMetamask() {
      if (typeof window.ethereum !== 'undefined') {
        window.web3 = new Web3(window.ethereum);
        window.ethereum.enable();
        const Address = await window.ethereum.request({ method: 'eth_requestAccounts' });
        this.$store.commit('address', Address);
      } else {
        console.error('MetaMask is not detected!');
      }
    },
  },
};

</script>

Balance of(this code)

<template>
</template>
<script>
import Web3 from 'web3';

export default {
  name: 'balanceOf',

  methods: {
async balanceOf(){ 
      const accounts = await window.ethereum.request({ method: 'eth_requestAccounts' });
  const account = accounts[0];
      const minABI = [
        // balanceOf
        {
          constant: true,
          inputs: [{ name: '_owner', type: 'address' }],
          name: 'balanceOf',
          outputs: [{ name: 'balance', type: 'uint256' }],
          type: 'function',
        },
      ];
      const a = 1;
      const contractAddress = '0x495f947276749ce646f68ac8c248420045cb7b5e';
      const openseaContract = new Web3.eth.Contract(minABI, contractAddress);
      const balanceOfAccount = await openseaContract.methods.balanceOf(contractAddress).call();
      console.log(balanceOfAccount);
      if (balanceOfAccount >= a) {
        window.parent.postMessage('Welcome to Pro Version ');
      } else {
        window.parent.postMessage('You dont have Genesis Card');
      }
    },
  },
};


</script>