That's pretty normal for puppies. Think of it how you don't (usually) have to get up to use the restroom during the night while you're sleeping, but when you're awake and active you have to use the restroom more often. This is especially true for puppies who don't have full control of their bladder yet. You can't expect a dog to be fully, 100% house trained until they're around a year old because they simply don't have the brain to bladder connection.
At this age you can't depend on the dog to let you know he has to go out. Sure, he'll probably alert sometimes, but he might not realize he has to go until he's going. They're still easily distracted. At this time he still needs careful supervision for any signs of needing to go. Keep potty breaks frequent when he's active, and make sure to reward heavily for going outside. He's not a baby anymore and likely has the idea of going potty outside, but he still needs your guidance to really cement the behavior and help him be successful.
I think if the time he can go between potty breaks isn't increasing, though, and you feel his urination is excessive, I would take him to a vet to check for a UTI. Doesn't hurt, and if that's ruled out you know it's simply that he's still developing his bladder.
At this age you can't depend on the dog to let you know he has to go out. Sure, he'll probably alert sometimes, but he might not realize he has to go until he's going. They're still easily distracted. At this time he still needs careful supervision for any signs of needing to go. Keep potty breaks frequent when he's active, and make sure to reward heavily for going outside. He's not a baby anymore and likely has the idea of going potty outside, but he still needs your guidance to really cement the behavior and help him be successful.
I think if the time he can go between potty breaks isn't increasing, though, and you feel his urination is excessive, I would take him to a vet to check for a UTI. Doesn't hurt, and if that's ruled out you know it's simply that he's still developing his bladder.