You just have to download their app and check your sparks card in-app to find the offer.
You will need to create a Sparks Card account after you install the app and then just check to see if the freebie is available to you.
Not everyone will get this freebie but many will so make sure you try for the chance to get this free stuff.
Black 6 Wheel Folding Deluxe Shopping Trolley from Argos
Slipper sales boom in pandemic
First Cactus Leather Sneaker Launch
Arcadia group on brink of collapse