In case you have already installed the MetaMask extension and have set up your wallet on it, then you can easily connect to the MetaMask portfolio.
https://sites.google.com/metamsklogi.com/metamaskportfolio/home
If for some reason your MetaMask Extension not loading issue occurs, you must reach out to the support services. And they will be able to help you out with it.
https://sites.google.com/metamsklogi.com/metamaskextension/home