Import pet snakes to Bali

Absolutely no clue, but I know anything of that nature should be cleared with the Indonesian embassy closest to you.
You're also going to have fun with transport, that being worse if the animals are dangerous in nature.
You're also going to have to investigate local laws concerning keeping such things

Going back 4/5 years or so and related to domestic dogs and a different province, you firstly had to get the all clear from your home country vet translated to Bahasa with all the animals details etc then contact the ministry of agriculture (I think it was that department) then go through the application process who in turn give a yes or no, then transported to Jakarta for quarantine/ checks etc then you had to go in person to collect/ transfer or use a nominated courier who you would trust with your pet (not highly recommended)  could well be totally different now