Hi,
I can develop that merchant web app with two-factor authentication.
Please contact me for more details and samples of my work.
Over 10 years of experience in PHP, WordPress, Magento, HTML5, PostCSS, CSS Modules, LESS, NodeJS, AngularJS, ElasticSearch, ReactJS, Gulp, AWS, Webpack, MongoDB, Socket.io.
Best regards,
Dmitry,
Los Angeles