how to enable completion notification to the user once the candidate completes the task

Summary:

Users usually assign activity packets which has details which has to be completed by the candidates. We are looking for the feature where once the candidate uploads or submits the details the respective user should receive a notification about the completion of the task.

Content (required):

Without this feature the user has to go back and validate it every time they assign a packet of tasks to the candidates.

Version (include the version you are using, if applicable):

Code Snippet (add any code snippets that support your topic, if applicable):