Azure Marketplace offers pre-configured RabbitMQ images that can be deployed directly onto Azure Virtual Machines. Niles Partners provides a RabbitMQ package optimized for Azure environments, facilitating straightforward deployment and management. https://azuremarketplace.microsoft.com/en-us/marketplace/apps/nilespartnersinc1617691698386.rabbitmq?tab=overview
You can also manually set up RabbitMQ on Azure Virtual Machines running Linux distributions like Ubuntu so you will need to create VMs, install RabbitMQ, and configure it according to your needs.
https://www.golinuxcloud.com/install-rabbitmq-on-azure
While your client prefers an IaaS configuration, it's worth noting that Azure provides managed messaging services like Azure Service Bus, which offer reliable messaging capabilities with simplified maintenance.https://learn.microsoft.com/en-us/azure/architecture/guide/design-principles/managed-services
Let's not forget that services like CloudAMQP offer managed RabbitMQ instances that can be deployed on various cloud platforms, including Azure. In this case you will combine the control of IaaS with the convenience of managed services. https://github.com/rabbitmq/rabbitmq-server/discussions/2464