Yes, You can use DOT 3, I prefer DOT 4 but if thats what you already have
then use it. UNLESS, if it has been opened and sitting for some time. Brake
fluid is hydroscopic, meaning it absorbs water through the air. If it has
been open then I would just toss it in an appropriate place.

Searcher

Did you read the cap on the reservoir ?????

And are you 200% sure that the can of  prestone brake fluid is brake fluid
???
How long has it been sitting there ????????
Bottle still sealed ??????
Did you forget you put lawnmower oil in it 2 years ago because you couldn't
find another empty bottle ????????

If you don't have a leak the reservoir doesn't need to be topped off.
If your brake pads wear down the level goes down and when you replace the
pads its back on max again
Ofcourse when you top it off the reservoir will be to full and the brake
fluid will drip all over the place when they do replace the brakes.