use gr.load

app.py

@@ -1,7 +1,4 @@
 import gradio as gr
 
-def greet(name):
-    return "Hello " + name + "!!"
-
-iface = gr.Interface(fn=greet, inputs="text", outputs="text")
-iface.launch()
+demo = gr.load("gradio/question-answering", src="spaces")
+demo.launch()