Here is how to add a data package to your SIM card.

To activate a new data package:

1. Log in to your customer account. 

2. Click "Manage" on the appropriate SIM card.

3. On the next page, click "Change".

4. Select your desired tariff, scroll down and click "Continue".

5. Finally, click "Confirm". 

The new data package will be active in a few minutes.