subsequent CR/DR for missing custom duty in the PO

Dear guru,

I got one PO from china buy from Germany, and it supposed to have custom duty of 6.5% but user forgot to enter the value, thus the condition in the PO is there but with 0 custom duty % maintained.

and user found this problem only after GR and IR are posted.

in this case, can your please advice me the details steps how to resolved it, maybe by subsequent dr or cr in the MIRO?

thanks and regards

CW