Let’s say a type 2 diabetic on insulin decides to fast. He stops taking insulin altogether. Can his blood sugar drop too low? Or is hypoglycemia only an issue for type 1 diabetics?
It is tricky, and not something you should embark on based on what well meaning people on the internet tell you.
Here are some points from the perspective of type 2 diabetes and a keto diet, I would imagine that some of them would be just as meaningful during fasting.
https://www.healthline.com/health/type-2-diabetes-ketogenic-diet#monitoring
Best bet? Find a doctor that is not fasting-adverse that is willing to oversee the process. There are blood tests for ketones that work just the same as your regular blood tests for glucose. Find the danger levels, test as many times as needed, and adjust as recommended by your doctor.
It may be nothing; with any luck you do your first with flying colors and find out that it is not a concern. But you want to go at it with lots of caution and test, test, test.