If tranactions of one dayie 23rd march is missing in quickbooks but of 24th march is there in banking,how do I book the expense?

I can show you how to update your transactions, AlkaSharma.

We can refresh the connection by manually updating the banking page. Let me show you how: 

1. Go to the Banking or Transactions menu and select Banking.
2. Select the bank. 
3. At the upper-right, click Update. 

Then, you can filter the date in the For Review tab. If you get the same thing, I'd suggest entering them manually or if there are a lot of transactions, you can import them into the system. 

Feel free to use these links for future reference: 

• Categorise and match online bank transactions in QuickBooks Online
• Exclude a bank transaction you downloaded into QuickBooks Online

Let me know if you have other questions. Take care and have a good one!