What you see above is a usage example of the verb “ought,” which has two different meanings.
1 “Ought” can indicate correctness or duty, often when criticizing the actions of another.
2 “Ought” can indicate that something is probable.
A lot of English learners struggle to use the word “ought.” This is because “ought” is what we call a semi-modal verb. It acts like a main verb in some ways and a modal verb in others. It is usually followed by “to” and it does not change its form depending on the person.
Replace the “to” with “not” if you are making a negative statement.
This short explanation ought to help you on your way to using “ought.”