app.py

import gradio as gr

def greet(name):
    return "Hello " + name + "!!"

subject = gr.Textbox(placeholder="subject")
foo_bar_btn = gr.Button("Foo bar.")
foo_bar_btn.click(None, [], subject, _js="responsiveVoice.speak('ciao')")

iface = gr.Interface(fn=greet, inputs="text", outputs="text")
iface.launch()