You can upgrade to some channels directly from your Sky Q box by tuning to the channel you want to subscribe to.
If you see the message "Upgrade your subscription now by pressing the red button":
Press the red button on your Sky Q remote.
Follow the instructions and enter your Sky TV PIN.
You’ll see the channel subscription cost and your new total monthly cost.
There'll also be a pro rata charge on your next bill if you subscribe part way through a month. For more details, see Viewing and understanding your Sky bills.
If you see the message "Upgrade your subscription online to download from this channel", you’ll need to visit Sky Upgrades.