I'm happy to help you import your bank transactions into QBO successfully.
To clarify, did you receive an error when importing them in QuickBooks? If so, your file isn't formatted correctly, or the mapping of the fields is incorrect. Let me show you how to import them successfully in QBO. I've listed our supported file formats below:
If all details are in their accurate columns, you can now proceed with uploading your transactions. Here are the instructions for your detailed reference.