1.InSign button call a microflow, in that retrieve all account and check the current username is match with list of account using a loop.
2.create a boolean variable make that as true if username exist else make that as false.
3.Put decision check boolean variable if true, then create a String variable like ‘AA’ and create a integer variable and declare 0.
4.Add two variable by creating a new string variable as String variable +toString(integer Variable) and then send this through mail.
5.followed by add show page to show the OTP validating page.
6.There check the current OTP is equal to entered OTP .
7.If username doesn’t exist then show message as user doesn’t available.