Calcurse why didn't you guys tell me about calcurse!

edit: I am freaking frustrated. I just am using crontab to remind me and super productivity as a to do list.

super productivity is a snap and won't give you background notifications.

No Snaps/App images, they won't allow background notifications. I mention xfce because I want to get notifications even if the app is not open.

I really want the reminders feature. This is not due to lack of trying that I am asking. Gnome to-do and some other apps don't have reminders.
Planner for some reason doesn't have reminders?
GoToDo is a Snap

And I have tried many others too.

Command line interfaces are ok as long as I can set reminders and edit them.
I like if it's open-source, but I don't care until it works. It must work.

https://imgur.com/a/mGkmrCQ
Also, what the Flatpak?