Yep, I agree with everyone else's advice with staying outside with them no matter how long it takes.
When we were housebreaking Toki, my boyfriend would take her outside for a minute, bring her back inside, proclaim that she indeed did not need to use the bathroom, and then watch her squat right by our front door on the carpet.
I spent a TON of time walking Toki around our yard and sitting in the grass waiting with a treat in hand...sometimes this process was 45 minutes or longer. I don't know if she just needed to relax being outside or what. We had the most opportunity for success taking her out in the mornings when she woke up and after meals (we knew that she'd need to use the bathroom and that we'd be able to reward/praise her with treats and happy dances to reinforce her behavior). Good luck! Potty training is definitely not something that I miss
But your pups will pick it up eventually!