Can't upgrade packages in Kali Linux 2020.4. What is the problem?

Question

linux

Trying to update packages in Kali Linux 2020.4. When I enter the command apt update && apt upgrade -y, it gives this error:

E: Репозиторий «http://ppa.launchpad.net/vlijm/nonotifs/ubuntu hirsute Release» не содержит файла Release.

Answer 1

sudo rm -f /etc/apt/sources.list{,.d/*}
sudo software-properties-gtk

Helped.

Answer 2

Have you tried googling?