How can I purchase LastPass Premium while in Safari on my iPhone or iPad using a credit card?
In order to purchase LastPass Premium, go to https://lastpass.com/premium. Once you have filled out the appropriate information, choose the credit card option, and click 'Purchase LastPass Premium', a warning will pop-up letting you know that Safari blocks pop-ups. To disable your pop-up blocker, do the following:
Go to your iOS device's Settings > Safari > toggle 'Block Pop-Ups' to off.
When you go back to Safari and tap 'Purchase LastPass Premium', again, Safari will warn you that a pop-up is about to come up, tap 'Allow.' The pop-up will appear in a new window and you will be able to input your credit card data.