How do you change the default Multicraft ftp IP?

A friend of mine installed multicraft on a dedicated Ubuntu server a couple of weeks ago. Everything's been working fine but I can't connect to with

Change the Level Type of Your Java Edition Minecraft Server - Knowledgebase - Shockbyte

Installing Multicraft on Ubuntu

How to Make a Minecraft Server

MySQL+Multicraft setup issues SpigotMC - High Performance Minecraft

IP Forwarding in BungeeCord - Knowledgebase - Anvilnode

How to install Multicraft on Ubuntu 20.04 - Utho

Multicraft - The Minecraft Hosting Solution - WHMCS Module

Multicraft Problem with FTP SpigotMC - High Performance Minecraft

Multicraft install including Web Server, PHPmyadmin and SQL on Debian Linux

Backing up and Restoring your Server - Knowledgebase - Virtual Gladiators

Multicraft - User Manual - Confluence

Multicraft - User Manual - Confluence

Installing Multicraft on Debian

Multicraft: No daemon detected SpigotMC - High Performance Minecraft

Multicraft Daemon Error SpigotMC - High Performance Minecraft