import gradio as gr

def test(value, key_up_data: gr.KeyUpData):
    input_val = key_up_data.input_value
    return gr.Dropdown(choices=[f"{input_val} {i}" for i in range(10)])

with gr.Blocks() as demo:
    d = gr.Dropdown(["abc", "def"], allow_custom_value=True)
    t = gr.JSON()
    d.key_up(test, d, d, show_progress="hidden")

if __name__ == "__main__":
    demo.launch()