You can configure the overflow as you like... and from how many lines you want the view more button to appear.

Component demo:

Code:Example

class AppExpandableText extends StatefulWidget {
  final String text;
  final TextStyle? style;
  final int trimLines;

  const AppExpandableText({
    super.key,
    required this.text,
    this.style,
    this.trimLines = 3,
  });

  @override
  State<AppExpandableText> createState() => _AppExpandableTextState();
}

class _AppExpandableTextState extends State<AppExpandableText> {
  bool _expanded = false;
  bool _isOverflowing = false;

  @override
  void didChangeDependencies() {
    super.didChangeDependencies();
    WidgetsBinding.instance.addPostFrameCallback((_) => _checkOverflow());
  }

  void _checkOverflow() {
    final span = TextSpan(text: widget.text, style: widget.style);
    final tp = TextPainter(
      text: span,
      maxLines: widget.trimLines,
      textDirection: TextDirection.ltr,
    )..layout(maxWidth: MediaQuery.of(context).size.width);

    setState(() {
      _isOverflowing = tp.didExceedMaxLines;
    });
  }

  @override
  Widget build(BuildContext context) {
    
    final textWidget = Text(
      widget.text,
      style: widget.style,
      maxLines: _expanded ? null : widget.trimLines,
      overflow: _expanded ? TextOverflow.visible : TextOverflow.clip,
    );

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      mainAxisSize: MainAxisSize.min,
      children: [
        textWidget,
        if (_isOverflowing)
          InkWell(
            onTap: () => setState(() => _expanded = !_expanded),
            child: Text(
              _expanded ? '...Ver menos' : '...Ver más',
              style: widget.style,
            ),
          ),
      ],
    );
  }
}