I am using Postman to test extracting data from Xero Api.
The BankTransactions call bring back right amount of bank transaction records, but the lineitems section is always blank.
While I can confirm that the BankTransaction have been reconciled and assigned to a Contact and Account I dont see this information in any of he records.
Below you can clearly see that recon have assigned this expense to Entertainment.
Based on the documentation Xero Bank Transactions the Line Items would contain info on the account the transaction was assigned to.
Without seeing the url of the API call, I am assuming the line item object is blank because the page parameter is not included in the URL. In the documentation it states in the description for the page parameter:
Up to 100 bank transactions will be returned per call, with line items shown for each transaction, when the page parameter is used e.g. page=1
https://api.xero.com/api.xro/2.0/BankTransactions?page=1