Expat can be registered as the BPJS health if they meet the condition of
number 2, the second point, b verses (in bahasa)
This verse is to cover those who enter indonesia under non working permit
and under the short permits of working visa (6 months)
For further detail please check the link below:
https://bpjs-kesehatan.go.id/bpjs/index.php/pages/detail/2014/11