Azure DevOps yaml-pipeline deployment: “Provider phase is not supported”

Question

Azure DevOps yaml-pipeline with deployment job fails with error Provider phase is not supported .

What am I doing wrong?

Azure DevOps Server Version Dev17.M153.5 .

trigger:
- master
jobs:
- deployment: ExperimentalDeploy
  displayName: Deploy my app
  pool: MyPool
  environment: experimental_environment
  strategy:
    runOnce:
      deploy:
        steps:
        - script: echo Hello world

Answer 1

It because deployment job is not available in Azure DevOps Server 2019:

Also in the YAML page when you change to Azure DevOps Server 2019 you couldn't see the deployment job: