I am working with the Docebo API and need to filter courses and sessions based on custom fields (additional fields). However, I am unable to filter courses using these fields in /learn/v1/courses. Could you please provide guidance on the following:

1. How can I retrieve and filter courses based on custom fields (additional fields) through the Docebo API?
2. Are there any specific endpoints or methods for querying custom fields associated with courses?
3. If custom fields are not directly accessible via the course API, is there an alternative solution?
4. Any API to filter sessions basis of additional fields?

Thank you for your assistance!