Accounting Export for Expenses Online.

The accounting section can be activated in the settings: Select DATEV-Export or generic CSV-Export in the "Extensions" tab  and enter the required information. After confirmation, an additional submenu item "Accounting" will appear under Invoicing and Expenses. There, invoices can be exported for accounting purposes. The accounting export contains all accounting-relevant information for each expense item.

Creditors' accounts can be overwritten under "Expenses" > "Accounting" > "Creditors" if necessary. Without overwriting, the standard creditors' account is used.
Expense accounts are stored in the settings under  "Expenses" > "Categories". Each expense item can be assigned to a category.

By the way, several expense items can be recorded for one expense
More info on expenses

1. All completed incoming invoices (= moved to the archive) are offered for export under "Accounting".
2. Select invoices via the gray filter area or individually on the left
3. Check accounts.
4. Choose "Export invoices".
5. The completed export is listed under "Exports" with the time period indicated and can be downloaded with or without documents and sent to the tax advisor (e.g., monthly).

Certified means: Using the test scenarios agreed upon with the manufacturer for this interface, DATEV has confirmed the technically error-free data exchange.

Image source for montage: Unsplash Frederica Galli gallifederica.it