How to upgrade/change subscription

Hello, I was just wondering how I could upgrade my subscription. Initially I wanted to use the service for only a month, but I have taken a liking to the service therefore want to pay for the service for the entire year because it is cheaper that way. How can I do this? I couldn’t find any options to change subscription type.

Thank you in advance

There is no 1 month subscription for Avast Free/Pro/IS/Premier.

It seems there is, for the VPN service at least, see screen shot. How do I make it an annual one?

Screenshot:

http://i.imgur.com/Un3D02G.png?1

No there isn’t.
You posted in the wrong forum.
This is the correct one > https://forum.avast.com/index.php?board=80.0

Oh, sorry and thank you