There is a list of exempted countries and if you are travelling to Fiji from those exempted countries, you do not need a visa to travel to Fiji.
Please see this list of exempted countries.
However, if your country of nationality is not in the list of exempted countries, you need a visa to travel to Fiji. All visa applications and payments must be submitted through the Fiji Immigration ‘Immi Hub’ platform, which can be accessed here.