When you sign up for an unlimited plus subscription, or after the 7-day trial period, we automatically send you an email with a voucher code. You can use it to activate the subscription in up to two more accounts.
So please check your inbox and your spam folder.
If the other accounts don't exist yet, you can register them in the app or on the website and then redeem the voucher there.
You can find more about redeeming it here: How do I redeem a voucher?
If you need more help with this, please contact our support team at: [email protected]