Help Request: Integrating Epsilon and Adyen in D365 Commerce POS

[mpfdev71]

I am working on integrating Epsilon Digital for managing provider signatures on electronic payments made via Adyen within Dynamics 365 Commerce POS.

1. Send transaction data to Epsilon to obtain the provider signature.
2. Pass the received signature to Adyen to complete the payment.

I have used and customized the implementation from the Fiscal Integration Sample available in the official Microsoft repository:
https://github.com/microsoft/Dynamics365Commerce.Solutions/tree/release/9.52/src/FiscalIntegration/PosFiscalConnectorSample

What Has Been Done So Far:

1. Created a new POS Request Handler:

• Based on ExecuteHttpRequestRequestHandler to manage HTTP calls.
• Sends a POST request to Epsilon to obtain the provider’s signature.
• Stores the response data.
• Extracted transaction data from the POS environment

Issues Encountered:

1. POS Runtime Errors when registering the custom request handler:

• Error: "Unable to register replacement request handler with nonreplaceable request type."
• The POS system does not recognize the new handler as a valid replacement.

How to correctly register the custom request handler in POS without conflicts?
How to properly pass the provider signature to Adyen within the payment request?