Explanation

Step 1: Create an Azure Function app
Azure Functions provide an excellent way to deliver a solution using WebHooks.
Step 2: Refactor the plug-in logic in the app.
Step 3: Publish the app
You can publish your function app to Azure directly from Visual Studio.
Step 4: Register a webhook for the app in the Plug-in Registration tool Use the Plug-in Registration tool to register a WebHook.
Step 5: Register a step in the webhook.
Registering a step for a WebHook is like registering a step for a plug-in.
Reference:
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/use-webhooks
https://docs.microsoft.com/en-us/powerapps/developer/data-platform/register-web-hook