I want to use ngx-doc-viewer read from input file

<input type="file" (change)="onFileSelected($event)" />

<ngx-doc-viewer [viewerUrl]="docUrl" [url]="docUrl" viewer="office" style="width:100%;height:50vh;"></ngx-doc-viewer>

`import { Component } from '@angular/core';

@Component({

selector: 'app-root',

templateUrl: './app.component.html',

styleUrls: ['./app.component.scss']

})

export class AppComponent {

docUrl: any;

onFileSelected(event: Event): void {

const input = event.target as HTMLInputElement;

if (input.files && input.files[0]) {

const file = input.files[0];

const reader = new FileReader();

reader.onload = (e: any) => {

// const arrayBuffer = reader.result as ArrayBuffer;

// const base64String = this.arrayBufferToBase64(arrayBuffer);

this.docUrl = e.target.result;

};

reader.readAsArrayBuffer(file);

}

}

arrayBufferToBase64(buffer: ArrayBuffer): string {

let binary = '';

const bytes = new Uint8Array(buffer);

const len = bytes.byteLength;

for (let i = 0; i < len; i++) {

binary += String.fromCharCode(bytes[i]);

}

return window.btoa(binary);

}

}`

this code note showing the word document for ex...