This is demo pipeline to check IF conditions in declarative way

Jenkinsfile

pipeline {
    agent any
    stages {
        stage ('First') {
            steps {
                echo "First"
            }
        }

        if (env.BRANCH_NAME == 'master') {
            echo 'First stage is enought, exit 0 shoul happened here'
            currentBuild.result = 'SUCCESS'
            return
        } else {
            echo 'Second and third stages must be executed'
        }

        stage('Second') {
            steps {
                echo "Second"
            }
        }

        stage('Third') {
            steps {
                echo "Third"
            }
        }

    }
}