Cloud CI/CD: Verify target environment alias before continuing

Questions
1

With the new CI/CD, I want to select the target environment based on the current branchname.

Eg. cloud/live goes to live, cloud/dev goes to dev, cloud/my-new-flexible-environment goes to my-new-flexible-environment.

I’ve modified the azure-release-pipeline.yml file to add this stage:

  # resolve which environment to deploy to based on triggering branch
  - stage: resolveTarget
    displayName: Resolve Target Environment
    jobs:
      - job: setTargetEnvironment
        displayName: Set Target Environment Alias
        steps:
          - script: |
              echo "Triggering branch: $(Build.SourceBranchName)"
              echo "##vso[task.setvariable variable=targetEnvironment;isOutput=true]$(Build.SourceBranchName)"
            name: setTargetEnvironmentAlias
            displayName: Set Target Environment Alias

Is there any way I can verify that there actually is an environment with an alias matching my current branch name?