Welcome to Vodafone Community
I see the Vodafone Network has let you know by email it's unlocking has been requested to Apple after accepting your Nuc online unlock request.
Please Note > The iPhone isn't actually usually unlocked to all networks at this stage.
Apple then process the Networks request and occasionally this can take approximately up to another 30 days sometimes from Vodafone's email to complete an unlock request made by a Network.
To complete the process please Periodically insert an active Alternative Networks Sim Card in the iPhone with hooking upto iTunes is only typically needed if its an iPhone 4 or older although it wouldn't harm to do so.
From the iPhone 5 onwards there's not normally the need to hook up to iTunes to complete the process.
When it's unlocked you should see a pop up message and the alternatives Networks name will show in the iPhone's status bar.
A Puk isn't required.
Current Phone > Samsung Note 9 _512Gb > Model: SM-N960 Hybrid-Duos.
Samsung Gear s3 Frontier Watch.