Yes.
It should be visible on the product unless the size or nature of the product makes this impossible. The UKCA marking needs to be affixed visibly, legibly and indelibly to the construction product or to a label attached to it. Where this is not possible or not warranted on account of the nature of the product, it shall be affixed to the packaging or to the accompanying documents.
Northern Ireland Information: Construction Products Regulation in Northern Ireland – GOV.UK (www.gov.uk)
UK information: https://www.gov.uk/guidance/using-the-ukca-mark-from-1-january-2021