npm i babel-cli -g

    npm i -D babel-preset-env

{
    presets": [
        [                
            env,{
                targets:{
                    browsers":[last 1 version]
                }
            }
        ]
    ]
}

babel entry.js -o index.js -w"

npm i -D babel-plugin-transform-class-properties

]
                }
            }
        ]
    ],pluginstransform-class-properties]
}