In QuickBooks Online, you can connect multiple business and personal accounts to keep your business up to date. I'd gladly show you how to do it.

You can copy and paste your bank's website URL in the search field to see if it is supported in QuickBooks.   However, if you can't find your bank under the available options, you can send a request support for your bank. You can refer to the attachment screenshots along with the steps for better reference.
 

1. Go to Transactions, then select Bank transactions.
2. Click Connect account.
3. Search for the name of your financial institution. If QuickBooks is unable to find your bank, you will get the message, “Hmm, we can’t find [name of the bank you entered] in our list of supported providers”.
4. Enter your Account provider name and Account provider sign-in URL, then click Request.

In the meantime, you can upload the bank transactions manually using a CSV file. Here's how:

1. Go to your bank website and export your bank data. Use CSV file format.
2. Click Transactions menu and select Bank transactions.
3. Pick Upload transactions.
4. Select Drag and drop or select files and choose the file you downloaded from your bank. Then click Continue.
5. Follow the on-screen instructions to complete the process.

For more details, you can visit this article: Manually upload transactions from your bank.

I'm adding these articles you can use to help you manage your bank transactions in QuickBooks Online:

• Review downloaded bank and transactions.
• Set up bank rules to categorise online banking transactions. 

I will always be available to answer any questions you have about managing accounts and transactions in QBO. Have a great day ahead!