How do I recover information from a bank account I can no longer log into?
I can provide some information on how to get a copy of those transactions from your QuickBooks Self-Employed account, @mje7.
If you still have the transactions in your QuickBooks Self-Employed (QBSE) you can go to the Transactions tab to download/export the transactions into a CSV file. But not, then I suggest reaching out to your bank's customer support to ask for a copy.
Here's how to export the bank transactions from your QBSE account:
Go to the Transactions tab.
Set the Type, Account to that specific bank, and the Date.