“Lookup” option missing in contextual menu

Hello there!

I used to be able to select “Look Up” in contextual menu after selecting a specific words in any websites. By doing so I can look up the meaning of words with the help of my built-in dictionary in my iPhone12.

However, that “look up” option somehow went missing in my menu recently and I just failed to find in back after many attempts in different means.

Does anyone have any ideas about this issue? If so please let me know as this issue has been bugging me for a long time….thank you in advance!