how to remove postgresql completely?

in my kubuntu postgres is install but i have to remove from my system.but when remove from my system by this command

dpkg -l | grep postgres

and :

sudo apt-get --purge remove postgresql-common

I get this message

E: Conflicting values set for option Signed-By regarding source https://apt.postgresql.org/pub/repos/apt/ noble-pgdg: /usr/share/postgresql-common/pgdg/apt.postgresql.org.asc != /usr/share/postgresql-common/pgdg/apt.postgresql.org.gpg

E: The list of sources could not be read.

what to do???