# Support
source: https://developer.mastercard.com/mastercard-supplier-payment-agent/documentation/support/index.md

## FAQ {#faq}

By renewing your key you should be prompted once again to download the P12 certificate and then the DER and PEM certificates will be emailed to you. Initiate a GET request directed at the endpoint, /supplier-agents/payment-instructions/{paymentId}. For more information, refer to the Get Payment Instructions Details section. You have three options when it comes to renewing your keys. This [article](https://developer.mastercard.com/platform/documentation/getting-started-with-mastercard-apis/renewing-your-keys/) provides in-depth information on the approaches you can take. Business Payment Service accepts any valid ISO alpha-three currency code. For more information, refer to the [ISO 4217 Currency Codes](https://www.iso.org/iso-4217-currency-codes.html). A sandbox key is intended just for testing purposes. In the sandbox environment, you can make any changes you want. A production key gives you access to the live production environment. Any changes you make in the production environment will affect customers and needs to be carefully considered.

## Get Help {#get-help}

### Contact us for technical support. {#contact-us-for-technical-support}