I can’t show the Material Design icon on screen

Question

I tried to put the menu of Material Design, but I was not successful. Please someone has how to check if something is wrong with my code?

angular js.

"styles": [
          "src/styles.scss",
          "src/customTheme.scss",
          "node_modules/material-design-icons/iconfont/material-icons.css"
        ],

The page.

<mat-sidenav-container class="sidenav-container">
  <mat-sidenav #drawer class="sidenav"
      fixedInViewport="false"
      [attr.role]="(isHandset$ | async) ? 'dialog' : 'navigation'"
      [mode]="(isHandset$ | async) ? 'over' : 'side'"
      [opened]="(isHandset$ | async) === false">
    <mat-toolbar>Menu</mat-toolbar>
    <mat-nav-list>
      <a mat-list-item href="#">Link</a>
      <a mat-list-item href="#">Link</a>
    </mat-nav-list>
  </mat-sidenav>
  <mat-sidenav-content>
    <mat-toolbar color="primary">
      <button
        type="button"
        aria-label="Toggle sidenav"
        mat-icon-button
        (click)="drawer.toggle()"
        *ngIf="(isHandset$ | async)!.matches">
        <mat-icon aria-label="Side nav toggle icon">menu</mat-icon>
      </button>
      <span>
        <img class="logo" src="/assets/img/logo-animal.svg" alt="image">
      </span>
      <span class="spacer"></span>
      <div  class="menu_dimension">
      <a href="#">Link</a>
      <a href="#">Link</a>
      </div>

    </mat-toolbar>
    <!-- Add Content Here -->
  </mat-sidenav-content>
</mat-sidenav-container>

The tag mat-icon not caught at all.