Jest - how to use mocked class instance

In my frontend React application, I am using auth0-js library for authentication. It exports WebAuth class. In the code, I create an instance by calling WebAuth Something like this:

import { WebAuth } from 'auth0-js'


const auth0Client = new WebAuth({ /* some options */ })

/* 
...
using auth0Client
...
*/

I've create a file called just like the name of the library in my __mocks__ folder. Thanks to that, Jest automatically mocked this library.

// __mocks__/auth0-js.ts
const auth0Mock = jest.genMockFromModule('auth0-js')

module.exports = auth0Mock

But, in my tests I want to check whether some method on auth0Client was invoked. How can I do this?