Azure Devops Pipeline Trigger based on branch

Question

My yaml pipeline is working fine which perform terraform install, init, validate, plan and apply if the changes are commit to main branch.

Here, i am trying to execute the terraform apply only if the commit happens in main branch, tried to set pipeline trigger but failed

Willing to implement PR stuff.

trigger:
  batch: true
  branches:
    include:
      - main
      - feature/*
pool:
  vmImage: 'vm'

stages:
- stage: TerraformPipeline
  jobs:
    - job: AKSDeploymentViaTerraform
      continueOnError: false
      steps:
      - task: PublishPipelineArtifact@1
        displayName: Publish Artifacts
        
      - task: TerraformInstaller@0
        displayName: Terraform Install
        
      - task: TerraformCLI@0
        displayName: Terraform Init
        
      - task: TerraformCLI@0
        displayName: Terraform Validate 
        
      - task: TerraformCLI@0
        displayName: Terraform Plan
        
      - task: TerraformCLI@0
        displayName: Terraform Apply
~~~