Register a Dynamics 365 Dataverse plugin to intercept record creation and make an external callout

Steps

1. Create a .NET class library implementing IPlugin with an Execute method; within Execute, retrieve the IOrganizationService and ITracingService from the service provider
2. Extract the target entity from the InputParameters collection (context.InputParameters["Target"] as Entity) and read the fields needed for the external callout
3. Use HttpClient (or WebClient in older plugin patterns) to POST to the external system from within Execute; wrap the callout in a try/catch and use ITracingService.Trace() to log request/response for debugging
4. Sign and register the plugin assembly using the Plug-in Registration Tool (part of Power Platform CLI or XrmToolBox); create a step on the Create message for the target table at the desired pipeline stage (Pre-Operation or Post-Operation)
5. For sandbox plugins (required in online environments), ensure the external URL is reachable from Dataverse's sandbox — private or on-premises endpoints are not reachable without a Dataverse-side outbound network configuration
6. Test by creating a record and inspecting the plugin trace log in the Power Platform admin center under Plug-in Trace Log settings