Cannot add friend by Line ID

Hi,

I try to add friend by using Line ID when call method it will open Line app and always show message **_"User not found."**_

example of code, friend id is "nyan"

``` objective-c
[Line addFriend:@"nyan"];
```

From your example you use **_hPtAUZX6w5**_ as Line ID, my question is how to get or generate this hash string ?

Thank you for your answer,
nonth
