[ngClass] cannot be detect

[Arios509]

Hi there, i would like to ask about the problem that the Angular 8 [ngClass] this one cannot be add into the

 <international-phone-number  placeholder="Enter phone number" 
              [maxlength]="20" [defaultCountry]="'us'" formControlName="mobile" name="phone_number" 
              [ngClass]="{ 'is-invalid': f.mobile.touched && f.mobile.invalid }"></international-phone-number>
              <div *ngIf="f.mobile.touched && f.mobile.invalid" class="help-block">
                  <div *ngIf="f.mobile.errors.required">Your mobile is required</div>
                  <div *ngIf="f.mobile.invalid">Your mobile is invalid</div>

              </div>

I try, the error will come out, but the ngClass couldnt be detect.

[jek-bao-choo]

@esoyke might fix this for you. https://github.com/esoyke/ngx-international-phone-number2 Put this there. He might help.