https://raw.githubusercontent.com/jaz303/jquery-grab-bag/master/javascripts/jquery.autogrow-textarea.js

<code>
(function($)
{
    /**
     * Auto-growing textareas; technique ripped from Facebook
     * 
     * 
     * http://github.com/jaz303/jquery-grab-bag/tree/master/javascripts/jquery.autogrow-textarea.js
     */
    $.fn.autogrow = function(options)
    {
        return this.filter('textarea').each(function()
        {
            var self         = this;
            var $self        = $(self);
            var minHeight    = $self.height();
            var noFlickerPad = $self.hasClass('autogrow-short') ? 0 : parseInt($self.css('lineHeight')) || 0;
            var settings = $.extend({
                preGrowCallback: null,
                postGrowCallback: null
              }, options );

            var shadow = $('<div></div>').css({
                position:    'absolute',
                top:         -10000,
                left:        -10000,
                width:       $self.width(),
                fontSize:    $self.css('fontSize'),
                fontFamily:  $self.css('fontFamily'),
                fontWeight:  $self.css('fontWeight'),
                lineHeight:  $self.css('lineHeight'),
                resize:      'none',
    			'word-wrap': 'break-word'
            }).appendTo(document.body);

            var update = function(event)
            {
                var times = function(string, number)
                {
                    for (var i=0, r=''; i<number; i++) r += string;
                    return r;
                };

                var val = self.value.replace(/&/g, '&amp;')
                                    .replace(/</g, '&lt;')
                                    .replace(/>/g, '&gt;')
                                    .replace(/\n$/, '<br/>&#xa0;')
                                    .replace(/\n/g, '<br/>')
                                    .replace(/ {2,}/g, function(space){ return times('&#xa0;', space.length - 1) + ' ' });

				// Did enter get pressed?  Resize in this keydown event so that the flicker doesn't occur.
				if (event && event.data && event.data.event === 'keydown' && event.keyCode === 13) {
					val += '<br />';
				}

                shadow.css('width', $self.width());
                shadow.html(val + (noFlickerPad === 0 ? '...' : '')); // Append '...' to resize pre-emptively.
                
                var newHeight=Math.max(shadow.height() + noFlickerPad, minHeight);
                if(settings.preGrowCallback!=null){
                  newHeight=settings.preGrowCallback($self,shadow,newHeight,minHeight);
                }
                
                $self.height(newHeight);
                
                if(settings.postGrowCallback!=null){
                  settings.postGrowCallback($self);
                }
            }

            $self.change(update).keyup(update).keydown({event:'keydown'},update);
            $(window).resize(update);

            update();
        });
    };
})(jQuery);
</code>

In page header:
<code>
<script src="https://code.jquery.com/jquery-3.6.0.js"></script>
<script src="https://code.jquery.com/ui/1.13.0/jquery-ui.js"></script>
<link rel="stylesheet" href="//code.jquery.com/ui/1.13.0/themes/base/jquery-ui.css">
<script src="js/jquery.autogrow-textarea.js"></script>
<script>
  $( function() {
    $('.txtQuestion').autogrow();
    $('.txtQuestion').css('overflow', 'hidden').autogrow();
  } );
</script>
</code>

In page:
<code>
<textarea class="txtQuestion" style="width:98%"></textarea>
</code>