Ion-input & mask

I’m using Ionic V4 and Angular 7
I need to create an input for fixed six digit so i use this code:

<ion-input text-center autofocus="true" type="number" maxlength="6" minlength="6" placeholder="code" [(ngModel)]="otp"></ion-input>

But i see that autofocus & maxlength & minlength have no effect :frowning:

I’ve tried also pattern="[0-9]{6}?" but the same does’nt works !!
Ionic 4 is still beta ?

Ei Ionic team, when you add Ionic 4 category in this community ?? :slight_smile:

Some help ?