Calendar reminder (used with a notification)

hello everyone
I am trying to make a calendar reminder for my app in app inventor and my first thought was that i can put an notification extension.I already tried taifun notification in different phones and it works fine on some until android level 7. On android 8 9 and 10 it works and when i clicked the send notification button it closes the app.
Why is that? Can anyone help me to find a way to fix that?

See Q6 in Taifun’s documentation for his Notification extension. Q6 : TaifunNotification from Pura Vida Apps works great on all my devices exept on my new S9 (Android version 8.0.0) Any ideas why not?
A : I have to check into this. Meanwhile you might want to try the New Improved Notification Extension by Tiziano1960…

The extension currently does not work with Android 8,9 and 10.

The improved notification does work on android 8 9 and 10?..Because the example scheduler when i import it on app inventor it says that blocks did not load properly.Changes to the blocks for screen 5169512143519744_Screen1 will not be saved. if you any example with the improved notification please help

Please read the documentation at the ‘New Improved Notification Extension’ link.

In the comments, the developer provides an example I attach here the aia file of the demo
scheduler20.aia that might work.

Does this extension work on 8,9 and 10? Maybe, maybe not. Contact the developer Tiziano1960 for advise.

These scheduler.aia does not work…thats why i am asking how can i make it to work with android 8 and up.I will send him a message.