If it’s not official document from the government , it’s not official. That’s the end. You can get document sign by the religious people from the mosque, again it’s not official or legal.
i already told u what I know about Indonesian marriage legality. You can have many of nikah siri, but if you don’t file it to the government, it’s not legal.
America only acknowledge legal document. You have to have paper trail for that.
Either u pull the trigger or keep worrying and u won’t know the outcome. That’s all I can say. If it were me, I will marry your fiancee in indonesia and file for spouse visa. It’s cheaper and less hassle