I manage to get the metrics (hits, thumbs_down, thumbs_up) for one solution article with the request

curl -v -u <api_number>:X -X GET 'https://<site_name>.freshdesk.com/api/v2/solutions/articles/<article_number>'

The answer is

{"id":<article_number>,"type":1,"status":1,"agent_id":<agent_id>,"created_at":"2015-04-01T16:40:28Z","category_id":<category_id>,"folder_id":<folder_id>,"title":"Solution Title","updated_at":"2018-11-20T14:00:49Z","description":"<p>Full description</p>","seo_data":{"meta_title":"","meta_description":"","meta_keywords":""},"tags":s"Installation"],"attachments":s],"cloud_files":s],"feedback_count":0,"thumbs_up":8,"thumbs_down":1,"hits":656}

Now, the question is how to get the metrics for all the solution articles.

The request 

curl -v -u <api_number>:X -X GET 'https://<site_name>.freshdesk.com/api/v2/solutions/articles/'

doesn't return anything.

Thank you!