First step:
Be ready with your Metamask account and log in.
Then click the “Add Token” button at the bottom. For reference, see the image below.

Second step:
When you already open the “Add Tokens” page, click on the tab “Custom Token” as shown on the screenshot below.

Third step:
Click on Custom Token and then copy and paste this MANGA TOKEN contract address: 0xc2cb89bbb5bba6e21db1dfe13493dfd7dcbabd68
MetaMask will display MANGA as a token symbol field and number 6 in Decimals of Precision field. Click on the Next button.

Fourth step:
All you have to do is click on the Add Tokens button.

The Manga Token will then be added into your MetaMask Wallet.