How to get Planner task Completed By dynamic content in Power Automate

You can use a template in Power Automate to send an email when a Planner task is completed. However, this template returns the Completed by field as a user ID, and not as a display name. And the dynamic content available for a completed task does not include Completed by. We can, however, get this data using an expression. Here’s how to do it (video at bottom of post):

1. After your trigger (When a task is completed), insert the Get user profile (V2) step.
2. Click inside the User (UPN) field, then select Expression from the dynamic content panel
   

3. Paste the following expression in the box and click OK

triggerOutputs()?['body/completedBy/user/id']

4. Now, in your next step (email, Teams post, etc. – however you’re sharing the completion message), use the dynamic content from the Get user profile (V2) step to insert Display Name.
   

5. Save and test your flow.