That’s right , you get a sticker to pop on a paper card. You get 6 and you can hand the card to anyone as a one time use deal.
I believe that was a one off that they did a little while ago as I nominated my neighbour who became a member, all members were aloud to nominate 1 person to obtain a membership, they do offer on the receipts a guest pass regularly which you can give to someone but each of these guest passes are single use only.
If you know someone with a card NHS or not , they just need to be a card holder they can add you as a member but it I believe can only be done the once. https://www.companyshop.co.uk/media/2321/nominated-membership-form.pdf
Or you can be recommended by a card holder. There is a PDF to download and you fill in your details and the card holders. That’s how we got ours as sister works in a hospital.
It's free to anyone working or retired in the employment areas listed in the description ie NHS police fire etc