Hey there @Melsssy.
If you are trying to refer to your My Account login details, your username will be the email address that you provided when you had set up your service,
If you are needing to register for your My Account, you can do this via our landing page.
Alternatively, if are not sure what details you did provide to your account, I recommend getting in touch with our support team via the My Optus app, as they can look to assist with this further from there.
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