Native Storage with iOs not working


I am trying to implement Native Storage on my application. But I can’t store a value.

I followed the tutorial offered by Ionic, but unable to store data during emulation on iOs.

Here is the code :'tokenaccess', {property: this.tokenAccess})
              () => console.log('Stored item!'),
              error => console.error('Error storing item', error)

Any ideas to solve this problem ?