I'm trying to connect quickbooks and I get this.This sign-in info isn’t working. (103)

Thank you for engaging here in the community, @sulaiman3.

To begin with, could you please tell me the name of your bank? This information will enable me to check for any reported issues or relevant details.

Next, verify your credentials and make sure that the username and password you're entering in QuickBooks are the same as the ones you use when logging into your bank’s website directly.

To update your login information in QuickBooks:

1. Go to the Transactions, then Bank Transactions.
2. Select the account that’s showing the error.
3. Click on the Edit (pencil) icon.
4. Then, click on Edit sign-in info.
5. Here, you can update your login credentials. Be sure to re-enter your username and password to make sure they are correct.

Try logging into your bank’s website:  
                            

• Open a new browser window and navigate to your bank’s website.
• Log in directly there. Sometimes, your bank might have added security measures or updates that you need to complete on their site before they allow access from third-party applications like QuickBooks.
  
  

Lastly, check for any notifications or messages from your bank:
 

• Look for any alerts or messages that might require your acknowledgment or some action from your end.

Open this article for additional information: Fix bank error in QuickBooks Online and QuickBooks Self-Employed.

Refer to this article for guidance on categorizing your transactions: Categorize online bank transactions in QuickBooks Online.

Should you continue to experience difficulties after following these steps, please don't hesitate to reach out again. We are available to assist you 24/7.

@sulaiman3 

Try opening your QBO account on any private/incognito browser.