No. Sudan doesn't ask visitors to fill in an online arrival form (also called an entry form, immigration card or landing card) before they travel. Visa required; visitors must register with the Aliens Department within 3 days of arrival.
Do I still need a visa for Sudan?
An arrival form is not a visa. Whether you need a visa or an electronic travel authorization depends on your nationality, so check Sudan's official immigration website or your own government's travel advice.