Alphanumeric user name would be using numbers and letters in the name. John1234 is an example. Remember that most naming conventions for websites or even some domains require strong user name/password encryption. And example would be. JohN_1234. Note the use of caps and underscore. This would less likely be able to crack or figure out by an unwanted user.
bhaskaran7010
Health
Ben10, Johnny5, THX1138...
The username you entered contains characters that are not letters or numbers. If you entered a space or a dash (-) you'll probably get this error.
Username is the public name that you are known by. Password is a secret alphanumeric that only you know and use to gain access to a software programme, user account, web site etc.
Unfortunately, you cannot change your Snapchat username. So, when you make your account, make sure that you like it when you choose your username.
You can make up a username.
You make a username and password so you should know it.
Alphanumeric codes are a mixture of codes from letters and numbers.
just type the username and password you want and you use that
You Can't :P You'd Have To Make A New Account To Get A New Username
All you do is login with what ever username or password you want and that is your username and password.