Should work

manifests/init.pp

@@ -5,11 +5,26 @@ class bright (
 ) {
   include nginx
   include liurepo::postgres
+
+  yumrepo { 'pgdg-common':
+    name     => 'pgdg-common',
+    baseurl  => 'https://download.postgresql.org/pub/repos/yum/common/redhat/rhel-$releasever-$basearch',
+    enabled  => 1,
+    gpgkey   => 'file:///etc/pki/rpm-gpg/RPM-GPG-KEY-PGDG',
+    gpgcheck => 1,
+    require  => Class['liurepo::postgres'],
+  }
+
+  package { 'postgresql':
+    ensure   => disabled,
+    provider => 'dnfmodule',
+  }
+
   profiles::letsencrypt::cert { fact('networking.fqdn'): }
 
   package {
     [
-      'postgresql-server',
+      'postgresql11-server',
       'postgis31_11',
       'python3',
     ]: