Plesk Update Manager fails to install system updates: Failed to solve dependencies: Plesk installation requires ‘epel’ OS repository to be enabled

Symptoms

System update fails on a server with Plesk:

Plesk installation requires 'epel' OS repository to be enabled.
Make sure it is available and enabled, then try again.

Exception: Failed to solve dependencies:
plesk-php74-sodium-7.4.30-1centos.7.220616.1430.x86_64 requires libsodium.so.23()(64bit)

Cause

EPEL repository is missing.

Starting from Plesk Obsidian 18.0.44, Plesk requires EPEL repository to be enabled.

Resolution

1. Connect to the Plesk server via SSH.

2. Install EPEL repo:

   # yum install epel-release