sudo nano /etc/php/8.1/apache2/php.ini   [On Ubuntu 22.04]

You may need to edit and mention to use older PHP version with latest Ubuntu.

After generating token, error occurs on /icingaweb2/setup on page Requirements

Deprecated: Return type of Icinga\Application\Libraries::getIterator() should either be compatible with IteratorAggregate::getIterator(): Traversable, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /usr/share/php/Icinga/Application/Libraries.php on line 20

known bug : https://github.com/Icinga/icingaweb2/issues/4837

Also we get a warning that apt-key is going to be deprecated so as a workaround used this.

https://www.digitalocean.com/community/tutorials/how-to-handle-apt-key-and-add-apt-repository-deprecation-using-gpg-to-add-external-repositories-on-ubuntu-22-04

curl -L https://packages.icinga.com/icinga.key | sudo gpg --dearmor -o /usr/share/keyrings/icinga2
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  1723  100  1723    0     0   9429      0 --:--:-- --:--:-- --:--:--  9467

@Vishavjeet,

To fix this issue, make sure that the LDAP module and other required modules are installed on your system.

You can use your package manager to verify their status.

dpkg -l | grep slapd    # For Debian/Ubuntu
rpm -qa | grep openldap # For Red Hat/CentOS

What should I do? Please help.

@Neil,

I have updated the article…

Thanks