To record invoice payments, read here (link).
When recording a payment for confirmed invoices, within the Payment Editor window,
- Check the "Deduct withholding tax" to display withholding tax fields.
- Select a withholding tax type.
- An automatic withheld tax amount will be display in the adjacent Amount field. Custom the amount when needed.
If you cannot find a applicable withholding tax type, you can manage the tax list (link).
After recorded, the withheld tax amounts will be displayed in the payment table for your reference.