# Merchant Center custom application user guide
Once the Merchant Center Application is installed, complete configuration by finishing some initial settings as described below.
## Set keys and secrets
Set all required Digital River API keys and secrets before you use the connector. Refer to [Create connector access keys](/commercetools-1/create-integration-access-keys.md) for information on how to create/retrieve the keys.
Each key and secret can be entered using the **API Keys** sub-menu in the commercetools **Digital River** settings found in the commercetools Dashboard menus as shown in the following example:
## Rotate keys and secrets
Updated keys can be entered via the screen above. See the Digital River documentation on [rotating keys](https://docs.digitalriver.com/digital-river-api/administration/dashboard/developers/api-keys/rotating-keys) for details of how to generate a new key and expire the old one.
Your new key is not used immediately. By default key, new values are cached for up to 10 minutes. This value is configurable.
Keys are refreshed immediately if an old key is no longer valid.
## Define Warehouse shipFrom addresses
Digital River orders require a **shipFrom** address for their tax calculations. You must define at least one address. Each address can be defined in the Warehouse sub-menu in the commercetools Digital River settings as shown in the following example:
The ID that is used must be unique and will be used to link a cart to a warehouse. Refer to [Authorize a payment](/commercetools-1/use-the-commercetools-merchant-center-custom-application/merchant-center-custom-application-user-guide/authorize-a-payment.md) for more information.
Existing addresses may be viewed and edited via the drop-down next to the New Address button.
## Perform a catalog sync
Products are automatically synced to Digital River when they are published in commercetools. You can also perform a full manual sync. This is useful if you encounter sync errors or if the Digital River connector was installed after products were already entered in your catalog.
### View sync status
The Catalog Sync screen shows the details of the following:
* Time of the last manual sync
* Duration of the last manual sync
* Indication of if a manual sync is running
* Status of synchronization for all variants. This could be from a manual or automatic sync.
### **Understand variant sync status**
For each variant that is synced, a line appears in the table with the following data:
| Column | Description |
| --------------- | --------------------------------------------------------------------------------- |
| Product ID | The commercetools product id for the variant. Clicking this will open the product |
| Variant ID | The commercetools index for the variant. Clicking this will open the variant |
| Product Name | The name of the product |
| Request Data | Contents of the request sent to the Digital River API when syncing |
| Sync Time | Time of sync attempt |
| Response Data | Contents of the response received from Digital River API when syncing |
| Response Status | HTTP status of the response received from Digital River API when syncing |
| Success | Indicates if the sync was sucessful |
The request and response data sections can be expanded using the arrow at the far right of the table row. These details are provided to help you diagnose any sync failures.
### **Filtering sync results**
To filter sync results, select a filter and then type a string to match in the filter box. Only exact matches are supported. You can filter by the following:
* Product name
* Product id
* Response status
The following is an example of filtering by response status:
## **Performing a manual sync**
Click **Sync products** on the commercetools **Catalog Sync** page to start a manual sync. The button changes to an indicator that the sync process is in progress
Sync results are not refreshed automatically. Click **Refresh results** to do this.
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://docs.digitalriver.com/commercetools-1/use-the-commercetools-merchant-center-custom-application/merchant-center-custom-application-user-guide.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.