Hello there, gracewang.

Welcome to QuickBooks Community!

One of the best features of QuickBooks Online is that we can import data or files. However, please note that we only support CSV, QFX, QBO, OFX file formats. You'll want to convert your XLS to any of our supported file formats.

Then, here's how to import bank transactions. 

Post again here if you have more questions related to this. Have a great day!