Create or validate a lead and optionally start initialization for calling
lead not provided)leadId not provided)leadId nor lead is provided.{ "error": "Either leadId or lead object is required" }lead.projectId.{ "error": "projectId is required in lead object" }"A call attempt has already been made to this phone number for this project""Phone number contains repeating digits pattern""already exists for this project and process"lead.projectId does not match the authenticated project for the API key.{ "error": "projectId does not match authenticated project" }{ "success": false, "error": "...temporarily blocked..." }429 blocks for your API key.500 and other server errors).