XPLMSetWindowTitle
XPLM_API void XPLMSetWindowTitle(
XPLMWindowID inWindowID,
const char * inWindowTitle);
Sets the name for a window. This only applies to windows that opted-in to styling as an X-Plane 11 floating window (i.e., with styling mode xplm_WindowDecorationRoundRectangle) when they were created using XPLMCreateWindowEx().