Using angular translate inside the ngOnInit() method

I am new to angularJs. I am not able to use the translate service inside the ngOnInit() method for the labels defined as arrays inside the ngOnInit().

import { TranslateService } from '@ngx-translate/core';
import {
  getLanguage
} from 'src/app/utils/localstorage.utils';


export class ViewModificationApprovalComponent implements OnInit {
constructor(
private httpService: HttpService,
public translate: TranslateService


) {
    translate.addLangs(['en', 'es']);
    translate.setDefaultLang(getLanguage());
  }

ngOnInit() {
    // this.translate.addLangs(['en', 'es']);
    // this.translate.setDefaultLang(getLanguage());
      payload: {
        profileName: 'channelProfile',
        schema: [
          {
            name: 'basic',
            label: 'Basic',
            sections: [
              {
                name: 'personalInformation',
                label: 'Personal Information',

I need the label 'Personal Information' to be translated into other languages. While I am trying to do it with by using label : this.translate.instant('lang.info'), it is simply displaying lang.info but not the translated language as out. Maybe it is not being able to access the this.translate service

You might not have set up the key -> translation dictionary properly which the TranslateService will use to convert given text to a certain language. You might consider using the translateService.setTranslation(languageKey, jsonKeyToTranslationObject); function or use a loader. Details can be found here.