“Supposed to” according to what?

If you’re in the US, Federal labor laws explicitly allow “meal periods” to not be paid, though short breaks must be paid. Neither is required to be offered to employees, though.

Source: www.dol.gov/general/topic/workhours/breaks

State laws differ, of course, and many states - e.g., California - have much more employee-friendly laws. However, even in CA, a meal period must be offered but isn’t required to be paid (unless it’s an on-duty meal break).