With holding tax deducting at the time of APP

Hi,

I configured the WHT of payment and Invoice and assigned the same to the vendor. I made the WHT base as manual and posted the amount manually both at the time of down payment and at the time of invoice.. But the system is again deducting the TDS while I am making the payment to vendor through APP. Could you please explain what settings I have to do in order to not to deduct TDS at the time of APP

Advance Thanks

Koteswara Rao