See what version of postgresql is running on port 5432

pg_lsclusters

11  main    5432 online postgres /var/lib/postgresql/11/main /var/log/postgresql/postgresql-11-main.log
13  main    5433 online postgres /var/lib/postgresql/13/main /var/log/postgresql/postgresql-13-main.log

If 11 is running on default 5432 port then you need to upgrade postgresql from 11 to 13,

pg_dropcluster 13 main --stop
pg_upgradecluster 11 main # if upgrade is successful drop the old cluster now
pg_dropcluster 11 main