PDF download error

Ionic Framework
1

Hello, I have a problem with my code

What I want to do is that when I press the button in my application it downloads a pdf file that is inside the app, but I have not achieved my goal.
So can you help me what am I doing wrong?

import { Component, OnInit } from '@angular/core';
import { ModalController } from '@ionic/angular';
import { AccesoriesService } from '../services/accesories/accesories.service';
import { ProblemaPage } from '../problema/problema.page';
import { File } from '@ionic-native/file/ngx';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-accesorios',
  templateUrl: './accesorios.page.html',
  styleUrls: ['./accesorios.page.scss'],
})
export class AccesoriosPage implements OnInit {
  EstadoAcc: string = 'Problema';
  loadAccesory: string = "";
  padding: string = "ion-padding ion-activatable ripple-parent rectangle";

  toWait: boolean = true;

  constructor(
    private DataAcc: AccesoriesService,
    public modalCtrl: ModalController,
    private file: File,
    private http: HttpClient

  ) { }

  ngOnInit() {
    this.loadAccesory = this.DataAcc.AccVer
  }

  CheckAcc(event: any) {
    this.EstadoAcc = event.detail.value;
  }

  async GoToProblem(ThatPro: string) {

    this.DataAcc.AccList = ThatPro

    const modal = await this.modalCtrl.create({
      component: ProblemaPage,
    });
    modal.present();
  }

  GoBack() {
    this.modalCtrl.dismiss();
  }

  downloadPdf() {
    const pdfUrl = 'assets/manuales/SeinmexCosechaArriba.pdf';

    this.http.get(pdfUrl, { responseType: 'blob' }).subscribe(response => {
      const blob = new Blob([response], { type: 'application/pdf' });

      const directory = this.file.externalRootDirectory + 'Download/';
      const fileName = 'SeinmexCosechaArriba.pdf';

      this.file.writeFile(directory, fileName, blob, { replace: true }).then(() => {
        console.log('Archivo descargado correctamente');
      }).catch(error => {
        console.error('Error al descargar el archivo', error);
      });
    });
  }
}

This puts me on the console:
ERROR TypeError: Cannot read properties of undefined (reading ‘then’)
at Object.next (accesorios.page.ts:59:72)
at ConsumerObserver.next (Subscriber.js:91:33)
at SafeSubscriber._next (Subscriber.js:60:26)
at SafeSubscriber.next (Subscriber.js:31:18)
at map.js:7:24
at OperatorSubscriber._next (OperatorSubscriber.js:13:21)
at OperatorSubscriber.next (Subscriber.js:31:18)
at filter.js:6:128
at OperatorSubscriber._next (OperatorSubscriber.js:13:21)
at OperatorSubscriber.next (Subscriber.js:31:18)