Gosh - Your son was diagnosed T2 at 12? That's pretty young, although not entirely unknown, but I would have thought highly unusual 8 years ago.
There are a good number of people who get along very well with the SGLT2 inhibitor class of meds, but then there are also some for whom it isn't good news.
If you were to Google it, I'm sure you'd find a mixed bag.
Of course, not everyone prescribed this medication will have issues, but it is important to have thread the following, if it has potential to be in the mix:
https://bnf.nice.org.uk/drug/dapagliflozin.html#importantSafetyInformations
It really is something warranting a good conversion with your son's medical team. If he is to take it, it is very important he has the equipment and supplies to test for ketones.
Good luck with it all.