Hi - thanks for the question
Azure PaaS is evergreen and updates are pushed automatically.
But there's a few things which are good to know, including how to implement a canary strategy and understanding how to monitor that updates were applied REF https://learn.microsoft.com/en-us/azure/api-management/validate-service-updates
In addition you should find details for what went into a release here https://github.com/Azure/API-Management/releases