How this works:

Iranians in Iran find a trusted Iranian in U.S. who will receive USD in his bank account, then use those funds to buy Gift Cards (online / spendable electronically) and physical (delivered to Iran).

Iranians in Iran find third parties in other countries to send USD to the U.S. bank account of the Iranian in the U.S.

What the article doesn't describe, is how and why these third parties sent USD to the Iranian in the U.S.

This matches well with "third party" P2P trading on Paxful or other KYC-free P2P trading platforms. The seller of bitcoin, (the Iranians in Iran) provide to the buyer of the bitcoin the name and bank account number of the Iranian in the U.S. The Iranian in the U.S. only needs to let the Iranians in Iran know when the funds arrive, and they release the BTC to the "third party" / buyer. The Iranian in the U.S. then withdraws the cash and buys gift cards with cash, and sends the code (secret) from the gift card to the Iranians in Iran.

The gift cards were likely used for online purchases for luxury items then received in Iran and those items resold for cash.

The bitcoin were likely received as payment for commodities or weapons -- possibly through corporations or intermediaries.

It may not have been exactly like this, but this is how bitcoin held by Iranians can be spent within the country.