How to handle "object may be null" when getting elements via querySelector/getElementById/etc?

Question

Frontend

Of course you can write something like: document.querySelector(`elmentname`) ? .classList.add("disabled")
But I would like to get an error if the element is not found, if for example I specified a wrong selector.
What would the compiler not swear and throw an exception when calling .classList.add("disabled") ?
How to do it right?