You can build an application, create a docker image and upload it to AWS ECR using Azure DevOps build pipeline. Later deploy this image from AWS ECR to AWS ECS Fargate container using the Release pipeline in Azure DevOps.
azure devops
Azure DevOps Environment – Kubernetes Generic Provider (existing service account)
You can use deployment job in pipeline to deploy your microservice in Kubernetes resource created in environment.
Helm upgrade and Kubernetes related issues
How to fix issues related to Helm chart deployment to Kubernetes
How to create azure service connection to connect to kubernetes
For an Azure RBAC enabled cluster, a ServiceAccount gets created in the chosen namespace along with RoleBinding object, so that the created ServiceAccount can do actions only on the chosen namespace.