Indonesia has a very nice amateur radio scene with activity on pretty much every mode and band you can imagine.
Foreigners can get a local callsign if they jump through a few hoops.
https://orari.or.id/cara-menjadi-anggota-orari/
IAR foreigner
Applications for IAR foreigners are submitted by the Central ORARI to the Directorate General of SDPPI online with the following requirements:
Radio amateur license from the country of origin that is still valid
Valid passport
Residence Permit in Indonesia (KITAS/KITAP)
Recent Official Photograph (file max 512 kb), with white background
B. HOW LONG IS THE PERIOD OF IAR WNA?
IAR foreigners are given a maximum of 3 (three) months and cannot be extended who have a Stay Permit of less than 3 (three) months.
IAR WNA is given for a maximum of 1 (one) year for Citizens who have a Limited Stay Permit or Permanent Stay Permit and can be extended according to the validity period of the KITAS/KITAP
Sorry about the rough translation - It's a Google job.
Sorry about the silly number of quotes - The forum software needs looking at
I kept my UK call active but I am now the very pleased holder of an Indonesian call as well (but I had to pass the test as I hold Indonesian citizenship)
The band plan is here
https://www.qsl.net/yb0emj/hamfrq.html
ORARI is the local amateur radio organisation - You'll find them as friendly as they are helpful.