$url =  "https://api.mch.weixin.qq.com/v3/marketing/busifavor/".$stock_id."/budget";
$json = '{
          "target_max_coupons": '.$allcount.',
          "current_max_coupons": '.$nowcount.',
          "modify_budget_request_no": "'.$request_no.'"
        }';

按照文档填写自己的参数后提交，结果返回空数组