Convert from puppet pki to icinga2 pki

I have been assigned with the task to reconfigure our Icinga2 server (and nodes) so that it no longer uses the Puppet-server as CA but the Icinga2 server itself.
Atm the nodes are configured with a piece of puppet code to configure the pki:

class { ‘::icinga2::feature::api’:
pki => ‘puppet’,

and I understand this needs to change into:

class { ‘::icinga2::feature::api’:
pki => ‘icinga2’,

What else do I need to do please?