Hi @Mark Thank you for reaching out to us, As I understand you are trying to create a billing support incident after purchasing Azure AD P2 license, For any billing related queries you can chat/contact support from the options provided here - https://azure.microsoft.com/en-in/contact/pricing/#contact-sales
In order to open a support ticket from the portal, you need to have subscription linked to your Azure AD, Refer to the steps here for creating a Azure support request - https://learn.microsoft.com/en-us/azure/azure-portal/supportability/how-to-create-azure-support-request
If you need any technical assistance with respect to Azure AD, either you can create a support request ( if you have a support plan) else post your query on QnA with these tags so that we can assist you on the same,
Let me know if you have any further questions, feel free to post back.
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