View the Posting, then Add the Doc

Not sure about the journal entry that will be created right after you’ll add this A/R Invoice (or any other document that results in journal entry)?

SAP Business One allows you to preview the journal entry that will be created before the document is added.

From within the document, click the Journal Entry Preview icon in the toolbar:

This way, you can review the journal entry and adjust the document if required, and only then, after you are happy with the expected result, add it.

In addition, as of SAP Business One 9.1, version for SAP HANA PL06 and SAP Business One 9.1 PL06, you can set the journal entry preview to display a separate line for each document row. In Document Settings window, select the check box Disable Journal Entry Lines Grouping in Posting Preview.