trigger taskTrigger on task ( after insert ) {
    set<Id> OwnerId = new set<Id>();
    Map < string, String > mapAccIdTasks = new Map < string, String >();
    CustomNotificationType notificationType = [SELECT Id FROM CustomNotificationType WHERE DeveloperName = 'Desktop'];
    for ( task oTask : trigger.new ) {
 
        OwnerId.add(oTask.ownerid);
        mapAccIdTasks.put(oTask.WhatId,oTask.Subject);

    }

    map<Id,user> userMap = new map<Id,user>([SELECT Id,UserRole FROM User WHERE Id In :OwnerId]);


    for ( task oTask : trigger.new ) {

    if(userMap.ContainsKey(oTask.ownerid)){
    	user oUser = userMap.get(oTask.ownerid);
    	if(oUser.userRole == 'Operations'){

    	

         Messaging.CustomNotification notification = new Messaging.CustomNotification();
        Set < String > recipientsIds = new Set < String >();
        notification.setTitle( 'File Attached to your Account' );
        notification.setNotificationTypeId( notificationType.Id );
    
        
        
            notification.setBody( 'File Id is ' + oTask.Subject );
            notification.setTargetId( oTask.Id );
            recipientsIds.add( oTask.OwnerId );
            notification.send( recipientsIds );
            }
    	}
    }
}