If you don't have a /etc/apt/sources.list.d/qgis.sources file yet, you can simply create it.

Either use an editor like nano, mousepad, geany etc to edit the file directly:

sudo YOUREDITOR /etc/apt/sources.list.d/qgis.sources

or create a qgis.sources text file with your normal user using any text editor and then move it using sudo mv qgis.sources /etc/apt/sources.list.d/

Purging a package using apt is done by apt purge packagename, so e.g. apt purge qgis.

If you don't have a /etc/apt/sources.list.d/qgis.sources file yet, you can simply create it.

Either use an editor like nano, mousepad, geany etc to edit the file directly:

sudo YOUREDITOR /etc/apt/sources.list.d/qgis.sources

or create a qgis.sources text file with your normal user using any text editor and then move it using sudo mv qgis.sources /etc/apt/sources.list.d/

Purging a package using apt is done by apt purge packagename, so e.g. apt purge qgis.

qgis.sources file is a template

You need to fill the Suites value:

Types: deb deb-src
URIs: https://qgis.org/debian
Suites: $your_distributions_codename
Architectures: amd64
Components: main
Signed-By: /etc/apt/keyrings/qgis-archive-keyring.gpg

So, replace the placeholder $your_distributions_codename by "jammy" (that was in your case the result of lsb_release -cs).

Suites: jammy