The Singapore-Malaysia Special Working Committee has agreed that the transport of all types of goods between Malaysia and Singapore will be facilitated during the duration of Malaysia's Movement Control Order. As such, those conveying essential services, or supplies (e.g. lorry drivers, vegetable supply truckers, frozen supply truckers) via land and sea crossings will be exempted from MOM's entry approval and SHN requirements.

Source: https://www.mom.gov.sg/newsroom/press-releases/2020/0325-mom-entry-approval-and-stay-home-notice-requirements-for-work-pass-holders-from-malaysia