Just got sent this text message which will be helpful to fill up.
Some information copied from the site:
Block-quote During the marketing launch of the Challenge App release, a one-off 25c per litre fuel discount is being offered to My Challenge members who download the Challenge App between 12am Tuesday 12 December and 11:59pm Monday 1 January 2024.
The one-off 25c per litre fuel discount will be available to use on the My Challenge members account as soon as the member has downloaded the App and logged into their account for the first time, and will be valid for 30 days.
If the one-off 25c per litre fuel discount is not redeemed before the end of the 30 day validity period, it will be automatically removed, and the members normal everyday fuel discount will apply.
Instead of text I got an email.
"Download and sign in to your My Challenge account via the App before 1st January 2024, and we’ll give you a one-off 25c per litre fuel discount (valid for 30 days)."