Jenkins error please

my jenkins file

pipeline {

agent any

stages {

stage('Git Progress') {

  steps {

    git branch: 'main', credentialsId: 'eub456', url: 'https://github.com/eub456/webtest.git'

  }

}

stage(‘Gradle Build & Image buil’) {

  steps {

    sh 'chmod +x ./gradlew'

    sh './gradlew clean build'

    sh 'docker build -t eub456/test .'

    }

}

stage ('Docker-hub login') {   

    steps {

           'step' docker.withRegistry('https://registry.hub.docker.com', 'test') {

           'step' app.push("${env.BUILD_NUMBER}")

           'step' app.push("latest")

            }

    }

}

}

}
-------------------------------------error-----------------------------

groovy.lang.MissingPropertyException: No such property: app for class: groovy.lang.Binding