退款时没有找到fmId，则从ext中获取

order-management/src/main/java/cn/freemud/management/adapter/PaymentSdkAdapter.java

@@ -12,6 +12,7 @@ import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Component;
 
 import java.math.BigDecimal;
+import java.util.Objects;
 import java.util.UUID;
 
 /**
@@ -42,7 +43,12 @@ public class PaymentSdkAdapter {
         refundRequestDTO.setNotifyUrl(refundNotifyCallback);
         OrderExtInfoDto orderExtInfoDto = JSONObject.parseObject(extInfoStr, OrderExtInfoDto.class);
         refundRequestDTO.setAppId(orderExtInfoDto.getAppid());
+        // 为空从extinfo中获取
+        if (StringUtils.isBlank(payNo) || Objects.equals("0", payNo)) {
+            payNo = orderExtInfoDto.getFmId();
+        }
         refundRequestDTO.setOrgPayFmId(payNo);
+
         refundRequestDTO.setOpenid(orderExtInfoDto.getOpenid());
         refundRequestDTO.setRefundId(getRefundSerialNo().toString());
         refundRequestDTO.setRefundDesc(StringUtils.isNotBlank(reason) ? reason : "商家退款");