Problem with Puppet environments import: ERF12-4115 [ProxyAPI::ProxyException]: Unable to get classes

Problem: When clicking “import environments from…” in Foreman/Puppet/Environments Foreman throws an error:

ERF12-4115 [ProxyAPI::ProxyException]: Unable to get classes from Puppet for zid_master ([RestClient::NotAcceptable]: 406 Not Acceptable) for proxy

Expected outcome: It should scan the directory /etc/puppetlabs/code/environments properly

Foreman and Proxy versions: Version 3.6.1

Foreman and Proxy plugin versions:

Distribution and version: Rocky Linux 8.8


2023-08-08T08:01:48.887+02:00 ERROR [qtp15430128-128] [p.t.a.rules] Forbidden request: access to /puppet/v3/environment_classes (method :get) (authenticated: true) denied by rule ‘puppetlabs deny all’.

Is there some ACL which should be changed?
If so, where is this ACL configuration?