A beagle dog or any other dog is okay to have in an apartment as long as your apartment allows dogs.
If your apartment doesn't allow any dogs or pets then no you cannot have a beagle dog or any other pet inside the apartment.
Then if caught with the beagle dog or other pet you could be evicted from your apartment but if your apartment or lease says that dogs or pets are allowed then yes a beagle is a good apartment dog.
When I lived in an apartment around 10 years ago my neighbor had a beagle dog and it was just fine being an apartment dog.
Beagles are great dogs but some apartments may or may not allow them and it's up to the apartment and landlord as to whether or not they'll allow the beagle or other dog or pets in the apartment.