1<button class="navbar-toggler" type="button" (click)="navbarCollapsed = !navbarCollapsed" [attr.aria-expanded]="!navbarCollapsed" aria-controls="navbarContent" aria-expanded="false" aria-label="Toggle navigation">
2 <span class="navbar-toggler-icon"></span>
3</button>
1<div class="collapse navbar-collapse" [ngbCollapse]="navbarCollapsed" id="navbarSupportedContent">