"The return type 'String' isn't a 'bool', as required by the closure's context" when declaring a path to a pdf file

I am trying to make a listview of items that opens the designated PDF file in an asset folder upon being tapped

void openPDF(BuildContext context, File file) => Navigator.of(context).push(
        MaterialPageRoute(builder: (context) => JournalViewerPage(file: file)),
      );

onTap: ()async {
                final path = 'assets/${journal_list.where((element) => element.fileLocation!)}';
                final file = await JournalAPI.loadAsset(path);
                openPDF(context, file);
              },

However element.fileLocation is throwing an error stated in the title above. Here is the model to my listview

class JournalModel {
  final String? journalTitle;
  final int? journalReleaseYear;
  final String? author;
  final String? topic;
  final String? fileLocation;

const JournalModel({
   this.journalTitle,
   this.journalReleaseYear,
   this.author,
   this.topic,
   this.fileLocation,
  });
}

And a few samples of the data i've inserted

import 'package:aplikasi_jurnal_mobile/models/journals.dart';

List<JournalModel> journal_list = [
  const JournalModel(
    journalTitle: 'Pembangunan Sistem Informasi Penjualan Obat Pada Apotek Punung', 
    journalReleaseYear: 2014, 
    author: "Tri Utami, Bambang Eka Purnama, Sukadi", 
    topic: "Medis", 
    fileLocation: '44-83-2-PB.pdf'
  ),

  const JournalModel(
    journalTitle: 'Pembuatan Aplikasi Pembelajaran Bahasa Inggris Pada Handphone dengan J2ME', 
    journalReleaseYear: 2010, 
    author: "Yusni Nyura", 
    topic: "Pendidikan", 
    fileLocation: '66-204-1-PB.pdf'
  ),
];

If it helps as well, here is the code to the API

import 'dart:async';
import 'package:flutter/services.dart';
import 'package:path_provider/path_provider.dart';
import 'package:aplikasi_jurnal_mobile/models/journals.dart';
import 'package:aplikasi_jurnal_mobile/data/journal_data.dart';

import 'dart:io';
import 'package:path/path.dart';

class JournalAPI {
  static Future<File> loadAsset(String path) async{
    final data = await rootBundle.load(path);
    final bytes = data.buffer.asUint8List();

    return _storeFile(path,bytes);
  }

  static Future<File> _storeFile(String path, List<int> bytes) async {
    final filename = basename(path); 
    final dir = await getApplicationDocumentsDirectory();

    final file = File('${dir.path}/$filename');
    await file.writeAsBytes(bytes, flush: true);
    return file;
  }
}

I have tried changing fileLocation = 'assets/filename.pdf' to fileLocation = 'filename.pdf'and called it using final path =${journal_list.where((element) => element.fileLocation!)}, but no luck. I also tried changing JournalModel to const whereas previously it wasn't, still nothing.