Unhandled Rejection (TypeError): this.web3.eth is undefined

My getWeb3.js file:

import Web3 from 'web3'

export default async () => {
    var web3Provider = null;
    if (typeof window.ethereum !== "undefined") {
        web3 = new Web3(window.ethereum)
        try {
            // Request account access if needed
            await window.ethereum.enable()
            // Acccounts now exposed
        } catch (error) {
            // User denied account access...
            console.log("MetaMask cannot be enabled!")
        }
    }
    // Legacy dapp browsers...
    else if (window.web3) {
        web3Provider = new Web3(window.web3.currentProvider);
    }
    // Non-dapp browsers...we use ganache
    else {
        console.log('Non-Ethereum browser detected. You should consider trying MetaMask!');
        web3Provider = new Web3.providers.HttpProvider('http://localhost:7545');
        console.log("ganache")
    }
    return web3
}

Here is how I call getWeb3, it always complain on this var accounts = await this.web3.eth.getAccounts(), saying this.web3.eth is undefined

export default class PaypalContract {
  constructor() {
    console.log(instance)
    if (!instance) {
      

```
  instance = this
  this.web3 = getWeb3()
  console.log("web3 init:",this.web3)
  this.contract = contract(PaypalContractMeta)
  this.contract.setProvider(this.web3)
  this.usdtcontract = contract(usdtContractMeta)
  this.usdtcontract.setProvider(this.web3)
}

return instance
```

  }

  async payToContract(coin_address,recipient,price,order_id) {
    //const { eth: { accounts: [ account ] } } = this.web3

```
var accounts = await this.web3.eth.getAccounts()
var account = accounts[0]
console.log('account:',account)
console.log("coin address:",coin_address)
const coincontractInstance = await this.usdtcontract.at(coin_address)
const contractInstance = await this.contract.deployed()
var priceUnit = this.web3.utils.toBN(price).mul(this.web3.utils.toBN(this.web3.utils.toWei("1")))
await coincontractInstance.approve(contractInstance.address,priceUnit,{from: account})
await contractInstance.deposit(coin_address,recipient,priceUnit,order_id,{ from: account })
await contractInstance.setExpiryDate(order_id,0,{ from: account })
```

  }