Visa regulations for Indonesia have changed due to the pandemic several times. There are some types of visa regulations to enter Indonesia i.e.
Visa Exemption Arrangement (VEA) is granted to foreign nationals who are citizens of a country, the government of a special administrative region, and certain entities subject to visa exemption to enter and stay in Indonesia. It is only valid for 30 days and cannot be extended. Currently, nine nationals from the ASEAN countries can enter without a visa (see https://www.imigrasi.go.id/en/bebas-visa-kunjungan/). These countries i.e. Brunei Darussalam, Cambodia, Laos, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam.
Visa On Arrival (VOA) is granted to foreign nationals who are citizens of a country, the government of a special administrative region, and certain entities that are subject to a Visitor Visa on Arrival to stay in Indonesia to carry out tourism activities or government duties in international activities that state or government. (see https://www.imigrasi.go.id/en/permohonan-visa-republik-indonesia-wisata-jurnalistik/). VOA price is IDR 500.000 per person, including children, and payable upon arrival in Bali by MasterCard, Visa, or Indonesian Rupiah cash. Currently, VOA covers countries i.e. Argentina, Australia, Austria, Bahrain, Belarus, Belgium, Bosnia, Herzegovina, Brazil, Brunei Darussalam, Bulgaria, Cambodia, Canada, China, Colombia, Croatia, Cyprus, Czech, Denmark, Egypt, Estonia, Finland, France, Germany, Hong Kong, Hungary, India, Ireland, Italy, Japan, Kuwait, Laos, Latvia, Lithuania, Luxembourg, Malaysia, Maldives, Malta, Mexico, Monaco, Morocco, Myanmar, Netherland, New Zealand, Norway, Oman, Peru, Philippines, Poland, Portugal, Qatar, Romania, Russia, Saudi Arabia, Serbia, Seychelles, Singapore, Slovakia, Slovenia, South Africa, South Korea, Spain, Sweden, Switzerland, Taiwan, Thailand, The United Arab Emirates, The United Kingdom, Timor Leste, Tunisia, Turkiye, Ukraina, United States of America, Vietnam, Yordania, and Yunani.
Other countries need to apply for a B211A Visit Visa before arriving in Indonesia (valid 60 days) (see. https://www.imigrasi.go.id/en/permohonan-visa-republik-indonesia-wisata-b211a/). You can apply for B211A Visit Visa either by visiting the Indonesian Consulate/Embassy near the place where you stay or by applying for an eVisa. For the eVisa application, you need a sponsoring agent to handle the immigration process and visa payment. For this process, the participants can use travel agents in Bali / Indonesia (see http://www.asitabali.org/en/keanggotaan/full-member). The Congress Committee only provides invitation letters for the Visa administration process. As a reference, you can see the useful links below.