Javascript – useEffect and useState from Child to Parent component

I have an issue with my project.
I need to pass the state of a countdown Child component to a Parent component, to make the Parent component visible or not if the time is 0.

this is my countdown component

import { Typography, Paper, Grid } from '@mui/material';
import React, { useEffect, useRef, useState } from 'react';

const formatTime = (time) => {
  let minutes = Math.floor(time / 60);
  let seconds = Math.floor(time - minutes * 60);

  if (minutes <= 10) {
    minutes = '0' + minutes;
  }
  if (seconds <= 10) {
    seconds = '0' + seconds;
  }
  return minutes + ':' + seconds;
};

function CountDown(props) {
  const [countdown, setCountdown] = useState(props.seconds);
  const [onTime, setOnTime] = useState(true);
  const timertId = useRef();

  useEffect(() => {
    timertId.current = setInterval(() => {
      setCountdown((prev) => prev - 1);
    }, 1000);
    return () => clearInterval(timertId.current);
  }, []);

  useEffect(() => {
    if (countdown <= 0) {
      clearInterval(timertId.current);
      setOnTime(false);
    }
  }, [countdown]);

  return (
    <Grid container>
      <Grid item xs={5}>
        <Paper elevation={0} variant='outlined' square>
          <Typography component='h6' fontFamily={'Roboto'}>
            Timer:
          </Typography>
        </Paper>
      </Grid>
      <Grid item xs={5}>
        <Paper
          elevation={0}
          variant='outlined'
          square
          sx={{ bgcolor: 'lightblue' }}
        >
          <Typography component='h6' fontFamily={'Roboto'}>
            {formatTime(countdown)}
          </Typography>
        </Paper>
      </Grid>
    </Grid>
  );
}

export default CountDown;

I want to pass the OnTime state to the Parent component:

export default function QuestionCard() {
  const [questions, setQuestions] = useState([]);
  const [clickedIndex, setClickedIndex] = useState(0);
  const [currentQuestionIndex, setCurrentQuestionIndex] = useState(0);
  const [value, setValue] = useState(null);
  const { isLoading, error, sendRequest: getQuestions } = useAxios();
  const { sendRequest: getAnswers } = useAxios();

  const handleSubmit = () => {
    setValue(true);
  };

  const handleSelectedItem = (index) => {
    setClickedIndex(index);
  };

  const handleChange = (e) => {
    setValue(e.target.value);
  };

  useEffect(() => {
    const transformQuestions = (questionObj) => {
      const loadedQuestions = [];

      for (const questionKey in questionObj) {
        loadedQuestions.push({
          id: questionKey,
          id_test: questionObj[questionKey].id_test,
          tipologia_domanda: questionObj[questionKey].tipologia_domanda,
          testo: questionObj[questionKey].testo,
          immagine: questionObj[questionKey].immagine,
          eliminata: questionObj[questionKey].eliminata,
        });
      }
      setQuestions(loadedQuestions);
    };
    getQuestions(
      {
        method: 'GET',
        url: baseURL_Q,
      },
      transformQuestions
    );
  }, [getQuestions]);

  let questionsTitle = questions.map((element) => `${element.testo}`);
  let questionId = questions.map((element) => `${element.id}`);

  return (
    <Grid container spacing={1}>
      <Grid item xs={10}>
        <Box
          sx={{
            minWidth: 275,
            display: 'flex',
            alignItems: 'center',
            paddingLeft: '50%',
            paddingBottom: '5%',
            position: 'center',
          }}
        >
          <Card
            variant='outlined'
            sx={{
              minWidth: 400,
            }}
          >
            <CardContent>
              <Grid container spacing={0}>
                <Grid item xs={8}>
                  <Typography
                    variant='h5'
                    component='div'
                    fontFamily={'Roboto'}
                  >
                    Nome Test
                  </Typography>
                </Grid>
                <Grid item xs={4}>
                  <CountDown seconds={300} />
                </Grid>
              </Grid>

              <LinearProgress variant='determinate' value={1} />

              <Typography
                sx={{ mb: 1.5, mt: 1.5 }}
                fontFamily={'Roboto'}
                fontWeight={'bold'}
              >
                {questionsTitle[currentQuestionIndex]}
              </Typography>

              <ButtonGroup
                fullWidth
                orientation='vertical'
                onClick={handleSubmit}
                onChange={handleChange}
              >
                <ListItemButton
                  selected={clickedIndex === 1}
                  onClick={() => handleSelectedItem(1)}
                >
                  Risposta 1
                </ListItemButton>
                <ListItemButton
                  selected={clickedIndex === 2}
                  onClick={() => handleSelectedItem(2)}
                >
                  Risposta 2
                </ListItemButton>
                <ListItemButton
                  selected={clickedIndex === 3}
                  onClick={() => handleSelectedItem(3)}
                >
                  Risposta 3
                </ListItemButton>
                <ListItemButton
                  selected={clickedIndex === 4}
                  onClick={() => handleSelectedItem(4)}
                >
                  Risposta 4
                </ListItemButton>
              </ButtonGroup>
            </CardContent>
            <CardActions>
              <Button onClick={goToNext} disabled={!value} variant='contained' size='small'>
                Avanti
              </Button>
            </CardActions>
          </Card>
        </Box>
      </Grid>
    </Grid>
  );
}

The idea is that onTime is true, the QuestionCard gets rendered with question and answers, if onTime is false, it gets rendered an alert or a text. How can I pass the onTime state from Countdown to QuestionCard? Thank you