Short answer: to represent Boolean in Oracle, use data type NUMBER(1,0) where 0 represents False and 1 represents True

Long answer: when there are many possible representations or implementations of something, one should choose the one that is (1) most widely adopted, (2) simple, and (3) clean. This is why NUMBER, in my view, is better even than Boolean, introduced in Oracle 23. I have provided detailed explanation here, because there exists another, duplicate thread on the same topic:
https://stackoverflow.com/a/79555398/17329826