Start by logging into your SaasAnt account.
Choose the 'Import' option & select 'Invoices'.
Upload your invoice file (Excel/CSV).
Map the fields from your file to QuickBooks fields.
Review the data & click 'Next'.
Validate the data & resolve any errors.
Finally, click 'Import' to add invoices to QuickBooks.
Always back up your data before importing.
For detailed steps, visit: How to Import Invoices into QuickBooks Online (U.S.).

https://support.saasant.com/support/solutions/articles/14000052899-how-to-import-invoices-into-quickbooks-online-u-s-