app.py

import os
import sys

import gradio as gr
from gradio.inputs import Textbox
from gradio.outputs import Textbox as TextOutput

def process(text):
    print('Hello')
    sys.stdout.flush()
    return f'Hi {text} (API_KEY: {os.environ.get("API_KEY")})'

interface = gr.Interface(
    fn=process,
    inputs=[Textbox()],
    outputs=[TextOutput()],
    theme='huggingface',
)

interface.launch(auth=[('a', 'b')])