Steps to connect MetaMask to Polygon.
1. Open and log in to your MetaMask wallet
2. From the account options, which is a circle icon, go to “Settings.”
3. Once you are in settings, select “Networks.”
4. Press the “Add Network” button.
5. You will be taken to a new screen. This is the most important step because this is where you will add the information to connect to the Polygon network.
Input the following new information and press save:
Network Name: Polygon
New RPC URL (Choose one of the following):
ChainID: 137
Symbol: MATIC
Block Explorer URL: https://polygonscan.com