Add the weights option.

app.py

@@ -93,7 +93,7 @@ demo = gr.Interface(
     inputs=[
         'image',
         gr.Textbox(lines=1, placeholder="Type the resolution (`WxH`) you want, e.g., `512x512`. Higher resolutions can be much slower for inference.", label="Resolution"),
-        gr.Checkbox(['zhengpeng7/BiRefNet', 'zhengpeng7/BiRefNet-portrait'], label="Models", info="Choose the weights you want.")
+        gr.Radio(['zhengpeng7/BiRefNet', 'zhengpeng7/BiRefNet-portrait'], label="Weights", info="Choose the weights you want.")
     ],
     outputs=ImageSlider(),
     examples=examples,