Zero confirmation payments?

In order to deliver a digital download to my customers as fast as possible, I’ve set “Number of confirmations required before accepting payment” to 0. The payments go through to my Electrum wallet immediately, but the order won’t be marked completed until the bitcoin network has at least one confirmation.

I’m using hard cron every 5 minutes.

How can I implement zero confirmations?

https://www.ads-software.com/plugins/bitcoin-payments-for-woocommerce/