There is no directive with "exportAs" set to "ngbDatepicker "

I am getting this There is no directive with "exportAs" set to "ngbDatepicker" issue in my angular 8 project.

My code given below:

admin.module.ts:

import { NgbModule } from '@ng-bootstrap/ng-bootstrap';

@NgModule({
    imports: [ 
        NgbModule
        ],

admin.component.html:

<input class="form-control " placeholder="yyyy-mm-dd " (click)="d.toggle() " name="dp " [(ngModel)]="model " [ngModelOptions]="{standalone: true} " ngbDatepicker #d="ngbDatepicker ">

Error:

   core.js:6014 ERROR Error: Uncaught (in promise): Error: Template parse errors:
    There is no directive with "exportAs" set to "ngbDatepicker " ("="d.toggle() " name="dp " [(ngModel)]="model " [ngModelOptions]="{standalone: true} " ngbDatepicker [ERROR ->]#d="ngbDatepicker ">

How to avoid this error?