Get the datetimepicker value to put it in input value

Question

I have a table that generates inputs in which I have a date / time that can be modified for a datetimepicker bootstrap v4 widget.

I display the widgets correctly, but I can not get the date chosen to include in the value of the input.

I need to do this so that I can then save the new dates to the database

can you help me ?

TD with script to generate input

<td>
    <input class="dateQalPicker" onchange="is_valid_blue(this,'<?php echo  $val[0]; ?>'); " type="text" value="<?php echo $val[0]; ?>" id="<?php echo $idtd ?>" style="border:none" />
</td>

to call datetimepicker

<script type="text/javascript">
    $(document).ready(function() {
        $('.dateQalPicker').datetimepicker({format:"YYYY-MM-DD HH:mm:ss"})
    });
</script>