Step 1: Select the settings button Settings icon near the top right of the screen and then choose Notifications.
Step 2: In the Notifications dialog box, choose to have Planner send you notifications when:
Step 3: Someone assigns a task to me. (Email, Teams, and mobile push)
A task assigned to me is late, due today, or due in the next 7 days. (Email only)
Step 4: Choose Save.