How to thermal print on a sunmi v2 printer a ListView widget that builds and displays a product in flutter

Question

I am using

import 'package:flutter_sunmi_printer/flutter_sunmi_printer.dart';

to print on a sunmi v2 printer. Printing strings and texts works fine:

SunmiPrinter.text(
     'Date: ' + DateConverter.dateTimeStringToDateTime(_order.createdAt),
     styles: SunmiStyles(align: SunmiAlign.left, size: SunmiSize.md),
   );
       SunmiPrinter.emptyLines(1);

But, I have a product that I want to print. The product is build like this:

ListView.builder(
  shrinkWrap: true,
  physics: NeverScrollableScrollPhysics(),
  itemCount: orderController.orderDetailsModel.length,
  itemBuilder: (context, index) {

    return OrderProductWidget(order: _order, orderDetails: orderController.orderDetailsModel[index]);

How can I print the output of that listview widget? The sunmi library expects either string or image. I tried making it an image first and then print the image but it doesn't like the format of the image. Any ideas?

Thanks!

I tried making it a screenshot image first but it does not seem to work:

Screenshot(
    controller: screenshotController,
    child:

ListView.builder(
  shrinkWrap: true,
  physics: NeverScrollableScrollPhysics(),
  itemCount: orderController.orderDetailsModel.length,
  itemBuilder: (context, index) {

    return OrderProductWidget(order: _order, orderDetails: orderController.orderDetailsModel[index]);
  },
),
);

screenshotController.capture().then((Uint8List image) {
  //Capture Done
  setState(() {
    _imageFile = image;
  });
}).catchError((onError) {
  print(onError);
});

ByteData bytes = await rootBundle.load(_imageFile);
final buffer = bytes.buffer;
final imgData = base64.encode(Uint8List.view(buffer));
SunmiPrinter.image(imgData);