Hello, @rgstg.
At this time, you can only add and sync your bank accounts in the Banking page. However, you can still track line of credit in QuickBooks Online (QBO).
You’ll have to set up a principal and expense account from your Chart of Accounts. You can out credit funds into another account by transferring funds between accounts.
For interest charges, you can add them by recording an expense transaction. See this article for more information: Enter, edit, or delete expenses in QuickBooks Online.
You can write a check in QBO if you’re going to send the bank or creditor a paper check. Read this record a payment to your line of credit article for more information.
We've already taken down your message and pass them to our Product Development team. Our engineers make improvements in QuickBooks Online by listening to our customers' suggestions and comments. Also, you can visit the QuickBooks Blog to check for new updates and features that we have.
Let us know if there's anything that you need. We're always here to assist.
