Here’s a thread that discusses another SGLT2 inhibitor, Jardiance: Type 1 and new drug Jardiance - #45 by JustLookin. Invokana comes up a couple times though. It sounds like dehydration may be a contributor to the amputation risk. Not sure about that though.
Jardiance and Farxiga are in the same class of drugs as Invokana (SGLT2 inhibitors), so they may provide the same benefits. Here’s an article that discusses how other meds in this class aren’t showing as elevated of levels of ampuation: FDA Reports Further Support for Canagliflozin-Amputation Link.
These may have other side effects though. Everyone is different, so maybe Invokana works better than these other drugs for you. Jardiance is supposed to be good for your heart though, so if you have any cardiovascular problems, that might be a good drug to consider.
Stay hydrated 