app.py

import gradio as gr
def hide_message(reg,sec):
    out = reg + " " + ''.join(chr(0xE0000 + ord(ch)) for ch in sec)
    print (len(out))
    print (out)
    print([out])
    return out


with gr.Blocks() as app:
    with gr.Row():
        with gr.Column():
            reg = gr.Textbox(label="Visible String")
            sec = gr.Textbox(label="Secret Message")
        btn=gr.Button()
    outp=gr.Textbox(label="Output Message")
    btn.click(hide_message,[reg,sec],outp)
app.launch()