Click on the upper-left corner of the MetaMask wallet, open the corresponding interface, turn on the 'Show Test Networks' switch, and click on 'Add Network'.
Click on 'Add Network' to open the MetaMask network page. Click on 'Custom RPC' to manually add the network. Enter the following information into the corresponding fields, and then click 'Save'.
Click on 'Connect Wallet', trigger your MetaMask wallet, enter the password to confirm the connection, click 'Continue,' and follow the steps on the webpage to claim at least 0.01 test ETH.