Log in to MyAccount at accounts.globe.com.ph
From the Account List page, select your Postpaid account and then click on the "Manage Account" button.
That takes you to your Account Dashboard. Click the "Retrieve PUK code" button in the "I WANT TO…" section of the page.
A pop-up will then appear. Enter your SIM card number in the field, and then click "Get PUK Code" to submit.
Your PUK Code will be displayed.