demo.load(

app.py

@@ -13,6 +13,10 @@ with gr.Blocks() as demo:
     text_2 = gr.Textbox()
 
 
-    demo.load("echo", echo, inputs=text_1, outputs=text_2)
+    demo.load(
+        echo, 
+        inputs=[text_1], 
+        outputs=[text_2]
+    )
 
 demo.launch()