On the Mothernode CRM Invoices screen, multiple invoice data export features are available in the upper-right portion of the screen:
These options produce export files in a .xls format, in which Export w/ LI is a more recent addition that also provides a list of invoices but adds specific line item details.
Export to Accounting provides an export file that can be used with Accounting programs including Quickbooks and Dynamics. Please see the support article titled Transaction Pro Importer for complete instructions for importing Mothernode CRM invoice data into Quickbooks.
Additionally, if you see Sync with Xero as part of the export options, then your organization is actively using the Xero API, in which Sync with Xero will sync selected invoices directly to Xero. Please see Syncing Mothernode Invoices with Xero for complete instructions regarding this process.