App.jsx

  loadWeb3 = async () => {
    const { setEthAddress } = this.props;

    if (window.ethereum) {
      window.web3 = new Web3(window.ethereum)
      const ethAddresses = await window.ethereum.enable()
      const ethAddress = ethAddresses[0]
      await setEthAddress(ethAddress)
    }
    else if (window.web3) {
      window.web3 = new Web3(window.web3.currentProvider)
    }
    else {
      window.alert('Non-Ethereum browser detected!')
    }
  }