Hi,
First define tax classification for each country in OVK1.
Then define customer tax classification (country US & MY) in OVK3 and assign the same in customer master. Tax Classification for US as 1 or taxable and 0 or not taxable for Malaysia depending on where your company code is located.
Similarly, you define & assign whether your material is taxable or not.
Where is your company located in US or MY? If it is export sale from Malaysia then, customer/material will not attract local taxes etc. So you need only to assign Malaysia tax as 0. If company code is in