a box prompt in a middle frame

I want to give a box prompt in a middle frame, it shows this warning

/root/anaconda3/envs/sam2/lib/python3.10/site-packages/torch/utils/_contextlib.py:116: UserWarning: You are adding a box after tracking starts. SAM 2 may not always be able to incorporate a box prompt for *refinement*. If you intend to use box prompt as an *initial* input before tracking, please call 'reset_state' on the inference state to restart from scratch.
return func(*args, **kwargs)
/root/work/segment-anything-2/sam2/sam2_video_predictor.py:873: UserWarning: cannot import name '_C' from 'sam2' (/root/work/segment-anything-2/sam2/__init__.py)

but in your paper says：
the model can be interactively prompted with different types of inputs (including clicks, boxes, or masks) on any frame in the video