Additional task-related features and issues within Microsoft Teams for business
Hi
My name is Daniel. I will be more than happy to assist you.
I'm afraid it's still not possible to do so, As of today, The tasks by planner app is still relatively very basic.
However, I believe this is indeed an important feature to be considered by the developer team. I invite you to submit a feature request or suggestions for improvements to the developer team.
Please select the help tab on the bottom of the left menu > select the give feedback option.
Disclaimer
This is a peer-to-peer support forum. I'm Non-Microsoft Staff, I don't work for Microsoft. Mostly everyone here are users helping other users.
Kind Regards