Create an Invoice through DI API

Hello,

I am trying to create an Invoice through the DI API but I am getting the following error:

Error: -10-In "To Whse" fields, enter valid values.

I don't understand why I am getting this message because I am entering a Warehouse Code that is registered in SAP.

I would also like to know if it is possible to link it to an existing Sales Order and if I could make an A/R Invoice as well.

Thanks!!