CVV is required when the physical card is not present. Like any transaction where the physical card is not inserted in a POS (point of sale).
You don't need CVV in a grocery because you give them the physical card. They magnetic strip (or chip) has all the info needed, so they don't need to enter CVV manually.
All online merchants requires CVV (booking a hotel, buying an airline ticket, online shopping, etc). There are very rare exceptions who doesn't require CVV like Amazon.com
I advise that you send an email to CIC immediately mentioning your UCI number, explain the situation, hopefully they will read your email before they start processing your file.