Interface of new function modules in OSS Notes

Dear Gurus,

I am implementing an OSS notes 1435326 which is creating new function module (RSAH_LAUNCH_EXCEL_WITH_TICKET)

In the correction instruction there is the code of the function module but I can't find the interface (import/export/table) anywhere.

Do you know where it is stored usually when an OSS notes is creating a new FM ?

Thanks for your help !

Manuel