The following error pops up when I type sudo apt update.
How can I resolve it.
Thanks in advance!!
Reading package lists... Done E: The repository 'https://kernel.ubuntu.com/~kernel-ppa/mainline bionic Release' does not have a Release file. N: Updating from such a repository can't be done securely, and is therefore disabled by default. N: See apt-secure(8) manpage for repository creation and user configuration details.