According to the Alchemy documentation,

using websockets with the web3-alchemy sdk requires setting up your web3 object with a websocket URL, like this:

const { createAlchemyWeb3 } = require("@alch/alchemy-web3");

const web3 = createAlchemyWeb3("wss://eth-mainnet.ws.alchemyapi.io/ws/<api-key>");

when it is set up correctly, you should be able to make a call, for example:

web3.eth.getBlockNumber().then(console.log);  // -> 7946893

The error you are seeing is due to an incorrect argument undefined React.js being passed into the alchemy web3 instantiation, basically:

const web3 = createAlchemyWeb3( undefined React.js ); // the error is here

You need to figure out why there is an undefined React.js showing up, and once you fix that error, your app should be able to load!

Not exactly sure but check your package.json file and see the version of react-scripts. If it defines an older version, try updating to the latest with :

npm uninstall react-scripts or yarn remove react-scripts

and re-install using

yarn add react-scripts or npm add react-scripts.

So in my case the problem was that in the code where you call for the json file from artifacts has to be named properly because in my case the name of the file was different so make sure that is not the case with you.