In order to view the flow of funds on the Matic Network using Matic.js, you will need to configure Matic’s testnet URL on Metamask.
To add Matic’s Testnet, click on the Network selection dropdown and then click on Custom RPC.
It will open up a form with 2 tabs on the top, Settings and Info. In the Settings tab you can add the URL
Once you’ve added the URL in the New Network field, click on Save. You will be directly switched to Matic’s testnet now in the network dropdown list. You can now close the dialog.