Can anyone help that How can i restrict user2 on object level

Hi everybody!!

When I use the 
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
 
on
 
...extends LightningModal {}
 
Show me a error:
 [Failed to execute 'dispatchEvent' on 'EventTarget': parameter 1 is not of type 'Event'.]
 
Help me, please!
 
Thanks!!