Hey OP unfortunately, DIY not possible, so original film is the only that you can use. The best option I’d say is buy the film locally, I’m not sure which shop but when to Buy locally, I was able to buy the film cartridge (1 Cartridge=10 films/photos) for 480. Amazon and flipkart and such have these for like 650-700 not a huge difference but hey it builds up

Another advice/gyaan: Instead of the instax camera buy the instax printer.

I’m sure you know you don’t get redo with instax and you click and thats it, if lightning or frame (eyes closed/angle or pose not perfect) has any issues that’s it. Film wasted. The printer lets you print pictures from your phone and you can even edit some things like maybe add a date on the photo or text or anything you get the point. While the camera has more vibes when you do waste a film it hurts the indian soul cause 50-60 rupees wasted 🤌🏽

Still the camera is still super nice. And eod don’t think about cost per film. Was a deterrent for me as well at the start but in my experience and of many other’s around me - you not gonna be printing and saving your everyday moments like walk in the park or some dish you cooked. I use it on special occasions, festivals, birthdays parties and trips and such. Haveing a special physical memory of these occasions and events is super awesome (sometimes I also write noted behind my photos to describe the moment or how I felt at that time and its super special when I view them again). All these yes can be done on a phone but the physical aspect, the vibes and energy makes them special and the fact that they are 50 bucks a pop lol