Install @ngx-translate/core using npm

@ngx-translate/core

npm install @ngx-translate/core --save

npm install @ngx-translate/http-loader --save

Add TranslateModule, TranslateLoader, TranslateHttpLoader into your AppModule class. app.module.ts would look like this

import {NgModule} from '@angular/core';
import { HttpClientModule, HttpClient } from '@angular/common/http';
import { TranslateModule, TranslateLoader } from '@ngx-translate/core';
import { TranslateHttpLoader } from '@ngx-translate/http-loader';

export function createTranslateLoader(http: HttpClient) {
    return new TranslateHttpLoader(http, './assets/i18n/', '.json');
  }

@NgModule({
imports: [TranslateModule.forRoot({
    loader: {
        provide: TranslateLoader,
        useFactory: (createTranslateLoader),
        deps: [HttpClient]
      }
}),],
declarations: [],
providers: [ ]
})
export class AppModule {

}