SonaType Nexus 3 proxy apt не работает

Не удаётся настроить proxy apt, установил SonaType Nexus 3 , при установки указал разрешение на анонимный доступ. Создал apt proxy для ubuntu 20.04. Скопировал ссылку, на клиентской машине создал файл /etc/apt/apt.conf.d/01proxy

Acquire::http::Proxy "http://192.168.66.226:8081/repository/apt/";
Acquire::https::Proxy "DIRECT";

Ввёл команду apt update, вывод:

Ign:1 http://security.ubuntu.com/ubuntu focal-security InRelease
Ign:2 http://archive.ubuntu.com/ubuntu focal InRelease
Ign:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease
Err:4 http://security.ubuntu.com/ubuntu focal-security Release
  404  Not Found [IP: 192.168.66.226 8081]
Ign:5 http://archive.ubuntu.com/ubuntu focal-backports InRelease
Err:6 http://archive.ubuntu.com/ubuntu focal Release
  404  Not Found [IP: 192.168.66.226 8081]
Err:7 http://archive.ubuntu.com/ubuntu focal-updates Release
  404  Not Found [IP: 192.168.66.226 8081]
Err:8 http://archive.ubuntu.com/ubuntu focal-backports Release
  404  Not Found [IP: 192.168.66.226 8081]
Reading package lists... Done
E: The repository 'http://security.ubuntu.com/ubuntu focal-security Release' no longer has 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.
E: The repository 'http://archive.ubuntu.com/ubuntu focal Release' no longer has 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.
E: The repository 'http://archive.ubuntu.com/ubuntu focal-updates Release' no longer has 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.
E: The repository 'http://archive.ubuntu.com/ubuntu focal-backports Release' no longer has 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.

Если в локальный сети через браузер перейти по ссылке http://192.168.66.226:8081/repository/apt/, то перекидывает на http://archive.ubuntu.com/ubuntu/