# zabbix_proxy -R config_cache_reload
zabbix_proxy: /usr/pgsql-13/lib/libpq.so.5: no version information available (required by zabbix_proxy)
zabbix_proxy [15173]: command sent successfully

[root@pg13 ~]# cat /etc/*release*
CentOS Linux release 8.3.2011
Derived from Red Hat Enterprise Linux 8.3
NAME="CentOS Linux"
VERSION="8"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="8"
PLATFORM_ID="platform:el8"
PRETTY_NAME="CentOS Linux 8"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:8"
HOME_URL="https://centos.org/"
BUG_REPORT_URL="https://bugs.centos.org/"
CENTOS_MANTISBT_PROJECT="CentOS-8"
CENTOS_MANTISBT_PROJECT_VERSION="8"
CentOS Linux release 8.3.2011
CentOS Linux release 8.3.2011
cpe:/o:centos:centos:8

[root@pg13 ~]# rpm -qa|grep zabbix
zabbix-release-5.4-1.el8.noarch
zabbix-sql-scripts-5.4.3-1.el8.noarch
zabbix-proxy-pgsql-5.4.3-1.el8.x86_64

[root@pg13 ~]# zabbix_proxy -V
zabbix_proxy: /usr/pgsql-13/lib/libpq.so.5: no version information available (required by zabbix_proxy)
zabbix_proxy (Zabbix) 5.4.3
Revision 68dc2b05cb 21 July 2021, compilation time: Jul 21 2021 10:38:52

Copyright (C) 2021 Zabbix SIA
License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it according to
the license. There is NO WARRANTY, to the extent permitted by law.

This product includes software developed by the OpenSSL Project
for use in the OpenSSL Toolkit (http://www.openssl.org/).

Compiled with OpenSSL 1.1.1g FIPS  21 Apr 2020
Running with OpenSSL 1.1.1g FIPS  21 Apr 2020

[root@pg13 ~]# getenforce
Permissive

sudo dnf install -y https://download.postgresql.org/pub/repos/yum/reporpms/EL-8-x86_64/pgdg-redhat-repo-latest.noarch.rpm
sudo dnf -qy module disable postgresql
sudo dnf install -y postgresql13-server
sudo /usr/pgsql-13/bin/postgresql-13-setup initdb
sudo systemctl enable postgresql-13
sudo systemctl start postgresql-13