The Oath of Allegiance (Judicial or Official Oath) is a promise to be loyal to the British monarch, and his or her heirs and successors, sworn by certain public servants in the United Kingdom, and also by newly naturalised subjects in citizenship ceremonies. The current standard wording of the oath of allegiance is set out in the Promissory Oaths Act 1868.

Can we conclude that does the uk have a pledge of allegiance?
yes