Follow the steps below:
1. Log in to your account at MogStation.
2. Click "Account Services" to proceed.
3. Click "Renew Subscription (Game Card)".
4. Enter the Final Fantasy XIV 60Days Game Time Card 20 digits Pin you purchased in SEAGM into 5 columns below accordingly. Each column should contain 4 digits. Click Next.
Your account will be added with the days of the subscription once completed.