app.module.ts to ngx-bootstrap

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { ModalModule, PopoverModule, RatingModule } from 'ngx-bootstrap';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    ModalModule.forRoot(),
    PopoverModule.forRoot(),
    RatingModule.forRoot()
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }