I have a One Plus phone

Step 1: Open Settings and select Notifications. 

Step 2: Select Skooly application

Step 3: Select Skooly and swipe right to enable "LED notifiactions"

Step 4: Now "LED notifications" as selected.

Step 5: Go back and select Apps.

Step 6: Select settings icon on top right and select "Apps auto launch".

Step 7: Scroll down and select Skooly application.

Step 8: Once selected it's done, notifications should work just fine for Skooly.