I want an app in which I can login using OTP and control my Arduino by bluetooth. This is my project for exibition and it's based on banking. steps I need. Open>Add mobile number>Send OTP to the added number ( after login new window open)> Option 1) Axis bank. option 2) Union bank ( Header must be 'select your account' ( both options must open another portal> header must be ' select amount' add two options 500 and 1000 > after clicking it give command to Arduino.