When creating roles, I have created a role that has FULL access to expense reports. The user can't select the category (account) when creating an expense report. What permission do I need to give access to so that a role that can create epense reports can add the category to the line items / expense rows of the expense report?

There is a one-to-one. Expense categories are a subset of GL. you don’t need a category for every GL.

But I need a category for every GL account that could be used in an Expense Report - right?