It seems they are already potty trained -- trained to potty on the carpet :(
I advocate a housebreaking method that involves scheduled feeding & watering, scheduled outside walks, 100% supervision, and crate confinement when 100% supervision is not possible.
You need to create the circumstances where the dogs go outside, and never has the opportunity to go inside. If they are fed endless food & water supplies, they will need to go at random times. This makes it more difficult to manage the situation. Feed and water at specific times, and then take them out immediately afterwards. The chances are very good that they will go within 15 minutes after being fed & watered.
Feeding 3 times a day is probably sufficient as they are pups.
Since these are young pups, they need bathroom breaks in addition to after feeding times. 8 week pups need to go out every 2 hours.
Once they are on scheduled feeding/watering and bathroom breaks, that maximizes the chance of success (going outside, according to schedule). In addition, you can minimize the chances of failure by providing 100% supervision or confining them to a crate when you cannot supervise.
When supervising, you catch them getting ready to go and you simply say "Outside!" and you take them outside. If you are intercepting accidents between scheduled bathroom breaks a lot, then you are probably overfeeding/watering or don't have enough bathroom breaks in yoru schedule.
If you cannot supervise, they are confined to a crate just large enough for them to lay down, stand up, turn & around. They have to be acclimated to the crate, and of course they can't be left in the crate longer than they can physically hold it (2hrs max at 8 weeks).
Under this method, if accidents still happen guess who is at fault? Yep -- the trainer
In addition to developing a housebreaking plan/routine, you also need to untrain the already learned behavior of going in the house. The plan described above will do that, but I also recommend that the spots they have used in the house be cleaned thoroughly with water & vinegar to completely remove the odor. If their scent is still there, they will continue to go in those spots.