Hey! Welcome to Sandbox.
Once you sign up to create a new Sandbox Account, you would be asked to verify the account using the 6-digit OTP sent to your email address.
Once you receive the email, you can enter the OTP or click on the verify button.
If you do not receive the email, make sure to check your spam folder.
NOTE: PLEASE RAISE A TICKET IF YOU DO NOT RECIEVE THE EMAIL.