==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3.1
- Deployed with iRedMail Easy or the downloadable installer? Downloadable
- Linux/BSD distribution name and version: Ubuntu 20 LTS
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MariaDB
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

Log below:
Hit:4 http://nova.clouds.archive.ubuntu.com/ubuntu focal-backports InRelease             
Err:5 https://packages.inverse.ca/SOGo/nightly/4/ubuntu focal InRelease                   
  403  Forbidden [IP: 192.95.20.194 443]
Reading package lists... Done                       
E: Failed to fetch https://packages.inverse.ca/SOGo/nightl … /InRelease  403  Forbidden [IP: 192.95.20.194 443]
E: The repository 'https://packages.inverse.ca/SOGo/nightly/4/ubuntu focal InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
[ INFO ] Installing package(s): postfix postfix-pcre libsasl2-modules mariadb-client mariadb-server postfix-mysql libdbd-mysql-perl php-cli php-fpm php-json php-gd php-curl mcrypt php-intl php-xml php-mbstring php-mysql nginx-full dovecot-imapd dovecot-pop3d dovecot-lmtpd dovecot-managesieved dovecot-sieve dovecot-mysql amavisd-new libcrypt-openssl-rsa-perl libmail-dkim-perl clamav-freshclam clamav-daemon spamassassin altermime arj nomarch cpio lzop cabextract p7zip-full rpm libmail-spf-perl unrar-free pax lrzip libclamunrar9 mlmmj python3-setuptools python3-pip python3-wheel python3-requests uwsgi uwsgi-plugin-python3 python3-pymysql memcached sogo sogo-activesync sope4.9-gdl1-mysql python2-dev curl libcurl4-openssl-dev python-setuptools python3-sqlalchemy python3-dnspython python3-requests python3-pip python3-pymysql python-jinja2 python-netifaces python-pycurl python-bcrypt python-dnspython python3-pymysql fail2ban geoip-bin geoip-database zlib1g libuuid1 libmnl0 curl lm-sensors netcat bzip2 acl patch cron tofrodos logwatch unzip bsdutils liblz4-tool
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package sogo-activesync
E: Unable to locate package sope4.9-gdl1-mysql
E: Couldn't find any package by glob 'sope4.9-gdl1-mysql'
E: Couldn't find any package by regex 'sope4.9-gdl1-mysql'
<< ERROR >> Installation failed, please check the terminal output.
<< ERROR >> If you're not sure what the problem is, try to get help in iRedMail
<< ERROR >> forum: https://forum.iredmail.org/

Seems package for Sogo nightly 4 dont exist. Please advise on how to continue installation.