1. Signup from the below link: Click here to sign up. or visit https://secure.simplymeet.me/register/
2. Verify your email, Go to the next step and set your username and copy it
3. Get back to your apps platform and paste the username in the feature settings.
4. Another way to view/change username, Visit SimplyMeeting Dashboard -> Profile -> Account Settings, Scroll to the end and edit/copy the username.