Update 2021-08-10: According to information from the Federal Foreign Office on Tuesday (10 August), numerous conditions apply to travel within Indonesia. For travel to or from Bali or Java, proof of vaccination (at least one vaccination) is required, for air travel a COVID-19 PCR test is also required, which must not be older than 48 hours, for all other means of transport an antigen test is sufficient, which must not be older than 24 hours. Similar requirements apply when travelling within Java and Bali. However, shopping centres in Jakarta and other cities in Java are allowed to reopen under certain conditions. However, proof of vaccination is required for entry and people over the age of seventy or under the age of twelve are not to be allowed to enter. For more details on travel restrictions, see the link below.
Auswärtiges Amt