Hi @TanviMehta ,
Could you please share a bit more about your scenario?
Do you want to create a Planner Task using PowerApps app, and added some Checklist items to it, and then assign this task to specific user?
If you want to create a Planner Task using PowerApps app, and assign it to a specific user, I think PowerApps app could achieve our needs. But if you still want to add some Checklist items to the created Planner Task, I afraid that there is no way to achieve your needs in PowerApps currently.
Currently, there is no property released under the "Create a task" action of Planner connector to add Checklist items to a task. More details about the "Create a task" action of Planner connector, please check the following article:
https://docs.microsoft.com/en-us/connectors/planner/#create-a-task
If you would like this feature to be added in PowerApps, please submit an idea to PowerApps Ideas Forum:
https://powerusers.microsoft.com/t5/Power-Apps-Ideas/idb-p/PowerAppsIdeas
If you want to create a Planner Task in PowerApps canvas app, and assign it to specific users, please check the following workaround:


Please check the following attached sample app for more details.
Best regards,