MS Access – Attempt to Use 2 Filtering Criteria with DSUM Function

Please can someone assist me with this problem I am having.

I am on my subform in MS Access and trying to use the DSUM function to sum the amount checked (using Checkbox).

On the main form I am trying to obtain the sum of the amount checked however it is giving me the total and not filtering by Allocation ID.

Below please find part of my function:
DSUM(“[Bags]”,”Allocation”,”chkDispatch=No”)

I am trying to filter chkDispatch and Allocation ID together so the sum of checked amounts can appear on the main form.

Please can anyone assist.

Pls email me on jterra@pngce.com.pg