не устанавливать пакет DKMS из PPA | как я его устанавливаю [дубликат]

эта команда не выполняется на моем компьютере: - sudo add-apt-repository ppa: morphis / anbox-support

duggal@duggal-X556UQK:~$ sudo add-apt-repository ppa:morphis/anbox-support
[sudo] password for duggal: 
 
 More info: https://launchpad.net/~morphis/+archive/ubuntu/anbox-support
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Hit:1 http://dl.google.com/linux/chrome/deb stable InRelease                   
Ign:2 http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal InRelease    
Hit:3 http://in.archive.ubuntu.com/ubuntu focal InRelease                      
Hit:4 http://in.archive.ubuntu.com/ubuntu focal-updates InRelease              
Hit:5 http://packages.microsoft.com/repos/vscode stable InRelease              
Hit:6 http://in.archive.ubuntu.com/ubuntu focal-backports InRelease            
Err:7 http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal Release      
  404  Not Found [IP: 2001:67c:1560:8008::15 80]
Hit:8 http://security.ubuntu.com/ubuntu focal-security InRelease               
Hit:9 https://debrepo.freedownloadmanager.org bionic InRelease                 
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/morphis/anbox-support/ubuntu focal 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.

дает мне ошибку