To activate your subscription when your trial ends, to apply a Coupon Code, or make any changes in the billing section of an account such as change subscription plan, you need to be signed in as the owner of that account.
Here are the steps you need to follow to activate your subscription in your Proto.io account:
1. If you do not have an account with Proto.io, proceed with creating one from the following link: https://proto.io/en/signup/
2. Sign in to your account and go to the Billing section from the upper right 'Manage Subscription' link in the account drop-down menu.
3. Proceed with your subscription activation by clicking on ACTIVATE SUBSCRIPTION.
4. Select a plan from the options listed (Monthly or Annually)
5. Fill out your account information, payment details (credit card details or Paypal) and click ACTIVATE SUBSCRIPTION.