How can I add a symbol after the text that I'm typing on input field. So when I type for instance a text after the text i would like to be a symbol but i don't want to be repeated. My actual code add the symbol every time i typed. I attached the code I would appreciate any help. Thanks!

```js
import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-pd',
  templateUrl: './pd.component.html',
  styleUrls: ['./pd.component.sass']
})
export class PdComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

  kup(event) {
    event.target.value = event.target.value+'e';
  }

}
```

```html
<input type="text" (keyup)="kup($event)">
```