Cannot create shipment and API return error message

I want to create shipment for my order, but the API return error as below:

I think this is because one of the item in my order is free gift thus the declared_customs_value is 0.
In this case, is there any way can support for item like free gift which price will be 0? Can we makedeclared_custom_value support 0 value?
If not, is there any suggestion/solution?