Onclick on the edit button keyboard should pop up

I am using ionic4/angular. give me a sample code that should pop up the keyboard when the input field is focused or when the edit button is clicked.i have tried many ways including Cordova keyboard plugin and install web-view also but nothing works.is there any module or package i need to install for this thing?

 <ion-input type="text" placeholder="Enter your first name" [readonly]="isReadOnly" name="profile"
              [value]="firstName" #nameCtrl="ngModel" ngModel pattern="[A-Za-z]+" minlength="3" maxlength="20"
              [(ngModel)]="firstName" (focusout)="nameCtrl.valid && out_profile()" #name no-padding>
enable_name() {
    this.isReadOnly = false;