Can you get a dog without papers microchipped?

We have an 11 month old pitbull we got him from my cousin about 3 months ago there's no papers on him cause 9 times out of 10 probably the same thing for his mom and dad and the other puppies cause my cousin breeds them as often as possible and my aunt wants to get him microchipped but I'm not sure we can 😪 can anybody give us advice