Thank you for your question.
At first I had to do a double take, I've seen this type of clunky, tortured writing before, it's from 'Course hero' (?)
Here's the actual text:
I am not aware any accounts, transactions, or agreements not authorised or properly recorded in the financial records underlying the financial information...
I am aware of no material transactions that have not been properly recorded in the accounting information.
'Underlying' simply means 'under', that is a subset of the aggregate mass of financial information.
There is the financial data which represents the entire set. Then, there's the recorded transactions, which can further be subdivided: cash flows, transfers, and etc. (They are accounting entries.)
Although your question is not about 'material transactions,' it is germane here. Material, which is an adjective here, means those transactions which are required to be recorded; that is, within the scope of what is required to be recorded in the accounting information and financial data.