To generate the C/C++ header file, click on the "Render" menu item and select the "Generate Code" menu item. This will produce a C/C++ header file in the same directory where the filter document is, with the same name as the document, but with the file extension ".h".
After the header file is created, the user will be prompted to open the file. If the user hits the "Yes," button, then the file will by launched in whatever application on the system is assigned the file extension ".h".
The user must have named the document before a header file will be written. If the FIR Filter document has not yet been named and the user tries to generate code, the user will be prompted to name the file at that time. Alternatively, if the file is not yet named, before trying to generate code, the user can name the file using by clicking on the "File" menu, and then selecting either the "Save" or "Save As" submenu item, and then be prompted to name the file.