For correct work of application:

1) Open “Settings ⟶ Apps ⟶ All apps ⟶ Prof Reminder”
1.1) Turn ON “Autostart”,
1.2) Turn ON “Other permissions ⟶ Start in background”,
1.3) Select “Battery saver ⟶ No restriction”.

2) In “Security ⟶ Boost speed ⟶ Lock apps” turn ON Prof Reminder.

3) В “Settings ⟶ Battery & performance” turn OFF “Power saving”.