Hi there,
Welcome to the Community. I'd be happy to share info about ITCs and HST in QuickBooks Online.
Based on what you've described, I recommend running a GST/HST Detail report. You can find this report by clicking Reports from your left menu and entering the report name in search field. From here you can check this report for the transaction in question. If you can't find this transaction, I suggest contacting our support team using this link here.
Feel free to ask other questions. I'm here to help.