Locale for datepicker not working on angular 13

 Hi team. I add 
```{ provide: OWL_DATE_TIME_LOCALE, useValue: 'vi-VN' }, ``` to my module like demo 
https://stackblitz.com/edit/angular-p5xkrl?file=app%2Fapp.module.ts,package.json

But it is not work. How can I fix it. Thanks team