Hi,
I’m the maintainer of KDE Plasma’s notification center. In Plasma 5.18 we’re introducing quick reply, where you’ll get a text field in the notification itself for quickly replying to a notification.
I recently added support for this to Telegram Desktop. It works by connecting to a (not yet standardized) signal NotificationReplied on the notification DBus interface. I realized it doesn’t work with the Snap version of Telegram as snapd’s AppArmor profiles won’t allow connecting to this signal.
Adding this signal to the builtin rules makes it work and should be safe to do.