do not send empty external_account_id

Author: auc-rhibbeler

src/create-seller.js

@@ -26,8 +26,8 @@ export const createSeller = async (
     last_name,
     email,
     company_name,
-    external_account_id,
     origin_country_code,
+    ...(external_account_id ? {external_account_id} : {})
   });
 
   console.log("Created ShipEngine Seller Account: ", response.data);

src/server.js

@@ -50,6 +50,7 @@ app.post(sellerEndpoint, bodyParser.json(), async (req, res) => {
 
     res.status(200).json(seller);
   } catch (error) {
+    console.error(error);
     res.status(500).json({ error });
   }
 });