=== create campaign ===
{"id":1,"name":"Q3 Invoices","status":"draft","recipient_list_id":1,"subject_set_ids":[1],"template_ids":[1],"message_type":"both","attach_mode":"none","attach_pdf":false,"attach_pdf_template_id":null,"attachment_id":null,"variable_config":{},"account_ids":[1],"rotation_strategy":"sequential","rotation_weights":{},"subject_rotation":"random","template_sequence_mode":"repeat","phone_selection":"ran
=== preview ===
Expecting value: line 1 column 1 (char 0)