GitHub pull requests triggering all pipelines in Azure DevOps

Question

I have 3 pipelines in Azure DevOps, on for each branch, and the code is on GitHub.

Whenever I do any Pull Request all my 3 pipelines get triggered. How can I avoid that?

The message says "PR automated for"

My 3 pipelines are using separated branches:

develop pipeline

trigger:
  branches:
    include: [develop]
  paths:
    include:
      - backend/*

staging pipeline

trigger:
  branches:
    include: [staging]
  paths:
    include:
      - backend/*

production pipeline

trigger:
  branches:
    include: [master]
  paths:
    include:
      - backend/*

Answer 1

I found in the docs PR trigger how to disable the run for all PRs adding:

pr: none

It goes in the root like this:

trigger:
  branches:
    include: [develop]
  paths:
    include:
      - backend/*

pr: none

Also:

Important

YAML PR triggers are supported only in GitHub and Bitbucket Cloud. If you use Azure Repos Git, you can configure a branch policy for build validation to trigger your build pipeline for validation.