From the spend portfolio nav click on airtime:
Click on any of the network providers of your choice
Enter the recipient's number or choose a contact from your device, then click continue
Click continue and select the data bundle you want to purchase
Click on the continue button then select the preferred asset e.g BTC
Enter your 4-digit passcode for security reasons
To continue click on the confirm purchase button
Once payment is confirmed you will see a pop-up message that shows “ Your MTN data purchase was successfully completed”.