As an admin, I would like to obtain additional information about the expenses from my submitters. How do I do that?

You can obtain additional information from your submitters by creating new custom fields for the expense creation form. Here’s how:

Click Admin View on the left sidebar.
Go to Settings on the left sidebar.
(OR)
Click Settings in the top right corner of the page.
Select Modules under Customization.
Click Expenses.
Go to the Fields tab.
Click + Add New Field.
Provide a name for the custom field.
Select the type of data that you’re going to enter for this custom field.
After you select an appropriate data type, a preview of how the custom field will look like while creating a record will be displayed below.
Click Save.

Submitters will now be able to add additional information in this custom field while submitting expenses for approval.