No provider for HttpClient

To resolve this problem HttpClient is Angular’s mechanism for communicating with a remote server over HTTP.

To make HttpClient available everywhere in the app,

1. open the root AppModule,

2. import the HttpClientModule from @angular/common/http,

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

3. add it to the @NgModule.imports array.

   imports:[HttpClientModule, ]