Answers for "No provider for HttpHandler!"

angular No provider for HttpClient

// open the root app.module.ts,
import { HttpClientModule } from '@angular/common/http';

// add it to the @NgModule.imports array.
imports:[HttpClientModule,  ]

No provider for HttpClient!

import { HttpClientModule } from '@angular/common/http';

NullInjectorError: No provider for HttpHandler!

import { HttpClientModule } from '@angular/common/http';

@NgModule({
 imports: [
   BrowserModule,
   HttpClientModule
 ],
 ...