Where is the Sim Network unlock PIN?

It is there. Let's go step by step:

• log into your fizz account,
• on left panel under your name, you see "Overview", "My Plans", "My Profile" ++
• click "My Plans",
• on right panel you see your name, $X.XX you paid, then a green button "Manage Plan",
• click "Manage Plan", you see full page of 13 choices, "Unblock SIM card -->" is 6th option on the left,
• click "Unblock SIM card-->", you see "Reveal your PUK code", there is a light grey on/off radio button right underneath it.
• click the on/off radio button, the PUK should then be shown to you(change from ****** to your #).
Don't rush, you will get there!!