So I was finally able to get it. I used the flutter_barcode_listener package with a little bit of customization.

void _handleBarcodeScan(String scannedCode) async {
if (!widget.focusNode.hasFocus) {
  return;
}
setState(() {
  // scannedcode came in with extra whitespace
  _scannedText = scannedCode.trim();
  
  // Scanner configured with enter after scan came in with `a` at the end
  if (_scannedText.endsWith("`a`")) {
    // # was transformed to 3 I needed to only remove the first 3 since 
       that is the only spot # will be
    _scannedText = _scannedText.replaceFirst("3", "#");
  }
  
  // If user manually entered text then often times _scannedText would be 
  // empty so instead I got the text from the widget
  if (_scannedText == "" && widget.controller.text != ""){
    _scannedText = widget.controller.text.toUpperCase();
  }

  // Replace all specific characters as needed
  _scannedText = _scannedText
      .replaceAll("½", "-")
      .replaceAll("``a`", "")
      .replaceAll(RegExp(r"\s+"), "") // Remove all spaces, including multiple spaces
      .replaceAll("¡3", "#"); // # would sometimes come in as that weird 
                              // character as well
});


widget.controller.clear();
widget.onBarcodeComplete(_scannedText);

}

@override

Widget build(BuildContext context) { return BarcodeKeyboardListener( bufferDuration: widget.bufferDuration, onBarcodeScanned: _handleBarcodeScan, child: TextField( controller: widget.controller, focusNode: widget.focusNode, textCapitalization: TextCapitalization.none, decoration: InputDecoration( labelText: widget.labelText, border: const OutlineInputBorder(), prefixIcon: IconButton( icon: Icon(Icons.clear), onPressed: () { widget.controller.clear(); setState(() { _scannedText = ''; }); }, ), ), onChanged: _onTextChanged, onSubmitted: (value) { }, ), ); } }