Hi @Anonymous
First of all you need to save the ID of SharePoint item in planner task.
I recommend to save the task in planner with Title = ID - SharePoint Title.
Next you'll build your flow with "When a item is deleted", this action don't brings all item information, it's bring only ID and deletion information (How delete, when deleted and etc).
Your flow structure need to:
- List all planner tasks
- Use a condition to see if Task Title has the ID
- Update Task details (to add how and when deleted)
- Update Task ( change status)
See the print bellow:
