How to contact Microsoft Support team. Full system memory dump on windows 2022

Please, very simple question

-We have no subscription for troubleshooting any issue related to Windows servers but we have for M365. We are a company ( no home)

How can we open a ticket (one ticket only, one time billing) for analyzing a full system memory dump. (windows 2022 datacenter)

we already analyzed the dump but we do not have access to the private symbols. The vendor already analyzed the dump and highly recommended to engage Microsoft.

-How much is the cost of the ticket?

-How can we contact and / or open that kind of ticket?

Best regards,