With the exception of asylum seekers, third-country nationals who are not family members of Belgians or EU citizens and who wish to settle in Belgium for more than three months must systematically apply to the Belgian diplomatic or consular post of their authorised place of residence an application for a residence permit before entering Belgium (visa application).
See the ADDE website (www.adde.be) or the Office des Etrangers (https://dofi.ibz.be)
There are several visas depending on the different bases on which residence is requested (family reunion, studies, work, etc.). Each application includes a series of conditions and documents to be produced to demonstrate the different conditions, the list of documents being issued on request by the Belgian Embassy or Consular Office of the authorised place of residence.