There are thousands of tokens deployed on the Ethereum mainnet and other EVM compatible chains. Because of this, MetaMask and many other wallets don't always display your tokens. You will have to programme MetaMask to display specific tokens.

Step 1: Under the ‘Assets’ tab, click on ‘Import Tokens’.

Step 2-1: Enter the name of the token in the search bar.

Step 2-2: If the token is well known, MetaMask should be able to detect it. Click on ‘Import Token’.

Step 3: If MetaMask is not able to find your token, click on ‘Custom Token’ and fill in the contract address of the token. Then click on ‘Add Custom Token’ to finalize the details.

Contract addresses for tokens can be obtained from block explorers like Etherscan or through indexes like CoinMarketCap or CoinGecko.