.. code-block:: console

  $ sudo tee /etc/apt/sources.list.d/debusine.sources <<END
  Types: deb
  URIs: https://deb.debusine.freexian.com/freexian/debusine
  Suites: trixie-devel
  Components: main
  Signed-By:
    -----BEGIN PGP PUBLIC KEY BLOCK-----
    .
    mDMEaaX1bBYJKwYBBAHaRw8BAQdAfpkAx9/TxpbnGHezlUiruo7YT0EcFHEQ9Swt
    65r8wEa0KUFyY2hpdmUgc2lnbmluZyBrZXkgZm9yIGZyZWV4aWFuL2RlYnVzaW5l
    iJAEExYKADgWIQT8mEBDdxrXXLXVVA1rNLmlWenTHAUCaaX1bAIbAwULCQgHAgYV
    CgkICwIEFgIDAQIeAQIXgAAKCRBrNLmlWenTHDBIAP0S1OwE1zTfV+0jFXYZW6J8
    dcS+fKF1S1YCi6cXLuWzZwEApcVXixlRDzOmQQBymyG35nf2ZRYFuhLOlkD/Ad/W
    Xg8=
    =VWZC
    -----END PGP PUBLIC KEY BLOCK-----
  END
  $ sudo apt update