How can I get the typed value from virtual keyboard

[JituMandal12]

Hello,
I want to get the value of button pressed on virtual keyboard. For example backspace. I am able to get enter, shift button clicked but not backspace button. Please help. I am using the following code.
I am using Angular 7.
<input
#userName
matKeyboard
[darkTheme] = true
(enterClick)="onEnterClick()"
formControlName="username"
maxlength="50"
>