JSON POST-параметров:
{"client_type":"#{client_type}", "id": "#{sheet_id}", "list": "#{list}", "list_id": "#{list_id}", "day":"#{day1}", "time":"#{front_time}", "name":"#{client_name}", "phone":"#{client_phone}", "client_field":"#{client_field}", "knop":"#{knop}", "with_buttons": "#{messengers_with_buttons}"}