I would like to ask a little about how to buy this keychain product at I saw it

[hanietanode]

Hello everyone,
I would like to ask about how to buy this keychain product at this link: https://tinycircuits.com/products/thumby?pr_prod_strat=collection_fallback&pr_rec_id=8b1357a57&pr_rec_pid=6634674192468&pr_ref_pid=10927371527&pr_seq=uniform
I saw it was announced that there will be a discount when buying from 2 products but I can't. I tried adding 2 or 3 products to the cart but the price is still the same when I check out.
Can someone please guide me?