@techddx You should create an array in the script editor, as the user is
entering the value in the table field you can add that value to the
array, and before inserting you can check if the value exists in the
array using 'includes'. const greetings = ['hi','hello'];
greetings.includes('hi'); // => true so you can prompt error
messagegreetings.includes('hey'); // => false, add this to greetings =>
['hi','hey'] refer:
https://www.w3schools.com/jsref/jsref_includes_array.asp