Neo4j Aura Professional is available through AWS, Azure, and Google Cloud Platform (GCP) marketplaces.
This article highlights the key differences across these Cloud Service Providers (CSPs) for Neo4j Aura subscriptions.
 

Feature	AWS	GCP	Azure
AuraDB	Yes	Yes	Yes
AuraDS	Yes	Yes	No
Billing	AWS Billing account	GCP Billing account	Azure Billing account

Purchasing Aura subscription from the CSP marketplaces allows customers to leverage their preferred Cloud Service Provider (CSP) for billing and management. Usage for instances created under such Aura tenants will be included in the CSP's billing and will not be a part of the Aura billing.