No. Guinea-Bissau doesn't ask visitors to fill in an online arrival form (also called an entry form, immigration card or landing card) before they travel. A visa and a yellow fever certificate are required.
Do I still need a visa for Guinea-Bissau?
An arrival form is not a visa. Whether you need a visa or an electronic travel authorization depends on your nationality, so check Guinea-Bissau's official immigration website or your own government's travel advice.