Ionic 4: Notification repeat itself with same content ( How to send different auto 4 notification a day )

I’m building an ionic 4 blog app So I need a notification system that sends like 4 times a day posts to the user.

What I found is Local Notification, The problem is when I register new notification repeat the same notification ( same post content ) every time the notification trigger

Even I set to choose a random post from my posts as the code below:

recurringNotification(issue) {

  const articles = (data: any[]) => {
    return data[Math.floor(Math.random()*data.length)];

  this.articlesService.getArticleList(issue, 100).subscribe(data => {
    let article = articles(data);

    let id = 1;
      id: id,
      text: article.title,
      data: { secret: },
      trigger: { in: 20, every: ELocalNotificationTriggerUnit.SECOND }

The code above it’s triggered every 20 Seconds just for testing! ( every 20 seconds I get same notification content and it overrides the previous one too )