Huge amounts of illegal businesses have been operating .
Seen many first hand examples of Russian, Chinese and Indian that were blatantly obvious, but there must be so many that aren’t so obvious.
I think they are better off though, imposing huge fines for operating illegally, and actually actively police it. Even a reporting system would help them
Apply in the country you’re in. So you’ll need to go to Cambodia, and apply online at the Cambodian embassy there. Wait until it’s granted, then come back.