The following guide will help you if you are facing a problem that does not allow you to select an Account after selecting an Item in the Supplier Invoice section. (Do note that the Account column will be available for manual selection, but not as an auto-populated column)
(If your "Account" column is already visible, you may skip ahead to step 1)
0.1. Right-click on the Header bar and select "Edit Column"
0.2. Right-click on the Header bar (light grey) and select "Hide/Unhide Column".
0.3. Ensure that the "Account" check-box is ticked by clicking on it, then click "OK" (Do remember: Save the setting by hovering on the header bar -> right-click & Save)
0.4. Column for "Account" should be visible on the table.
1. Item has been selected but entry cannot be made under "Account" column.
2. Click "Setup", then "Item Details", then "Item"; select the item you intend to enter in the Payment Voucher, then click "Edit"
3. Take note of the Group Name of this Item.
4. Select "Item Group" in the Menu; in the "Item Group Registration" tab, select the Group you intended to choose; then click "Edit"
5. In the "Item Group Registration" tab, ensure the checkbox for "Changable A/C at Document", then click "Update"
6. Returning back to the Supplier Invoice entry. screen,. The option to select an Account for that Item will now be available.