@Lhorie27 

The built-in importer tool offers only limited functionality. 

https:// quickbooks.intuit.com/learn-support/en-us/help-article/import-export-data-files/common-questions-importing-data-quickbooks-online/L4OYJRFdj_US_en_US

You need to have a 3rd party tool to import other transaction types (e.g Bills, Journals).