Hello there, @rahulraja.
I'm here to help you bring your bank transactions to your QuickBooks company. I'd like to know if you've received an error code or notification when clicking the Update button?
As of now, I suggest, you can click on the Update button in the Banking menu. This is done to make sure that the connection between your financial institution and QuickBooks is refreshed.
If you're unable to see the bank transactions, there are times that the bank updates their website's URL. Try copying your bank's URL. Then, paste it on to the banking page. Here's how:
To know more details about reconnecting your bank accounts in QuickBooks, you can review this article: What to do if you see a bank error or bank transactions won’t download.
I've added this article for your future task if you're still not able to see the transactions: Manually download online bank transactions in QuickBooks Online.
I'll be here if you have other questions about QuickBooks. Just let me know in the comment section below. Take care.