How to properly configure a webhook via the Plugin Registration Tool ?

Hello everyone,

I was trying to send data to an Azure function via the webhook configured in the PluginRegistrationTool.
The link to my webhook is : https://siteurl.azurewebsites.net/api/Function1?code=CUMlwLUSfb3LuZmHKANDcq454Esb0WEHh0VW5dZa1jEbCNV8gHD/aA=

According to the documentation : https://docs.microsoft.com/en-us/dynamics365/customer-engagement/developer/use-webhooks#register-a-webhook if i undestood properly it : 

* in the Endpoint url it should be : https://siteurl.azurewebsites.net/api/Function1 

* and the webhookkey should be : CUMlwLUSfb3LuZmHKANDcq454Esb0WEHh0VW5dZa1jEbCNV8gHD/aA= (also tried with ?code=CUMlwLUSfb3LuZmHKANDcq454Esb0WEHh0VW5dZa1jEbCNV8gHD/aA=)

Then i create a simple step for example  update on account, i get the following plugin error :

Microsoft Dynamics 365 can’t complete your request. The webhook service endpoint may be configured incorrectly or is not available. Contact the service endpoint owner or your system administrator to validate your configuration. If the problem persists, contact Microsoft Dynamics 365 customer support for help. If you contact support, please provide the technical details."

Anyone can point out my issue here ?

Thanks a lot,

Clément