By default, Binance Chain Extension Wallet will only show BNB in your wallet. In the event there are token other than BNB is transferred into your wallet. Please follow the following steps :
1. Firstly, check the transaction details and wallet destination on BSC scan. https://bscscan.com/
2. Please follow the following steps only if transaction is successful.
3. Login/Open Binance Extension Wallet and click on the "+" sign.
4. You should see there are 2 tabs : "Search" and "Custom Asset".
5. If you know the name of the token just add in "Search".
6. Otherwise you may also add via "Custom Asset" by keying the contract number which can be obtain in BSC Scan or Coingecko website.