No. Benin 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 for many nationalities, via eVisa.
Do I still need a visa for Benin?
An arrival form is not a visa. Whether you need a visa or an electronic travel authorization depends on your nationality, so check Benin's official immigration website or your own government's travel advice.