app.module.ts

import { TranslateHttpLoader } from '@ngx-translate/http-loader';
import { TranslateLoader, TranslateModule } from '@ngx-translate/core';

export function HttpLoaderFactory(httpClient: HttpClient) {
  return new TranslateHttpLoader(httpClient, environment.feServerUrl + '/assets/i18n/', '-lang.json');
}
@NgModule({
  imports: [
    // imports go here
    TranslateModule.forRoot({
      loader: {
        provide: TranslateLoader,
        useFactory: HttpLoaderFactory,
        deps: [HttpClient]
      }
    })
  ]
})