Baby Rottweiler

I just got a puppy 3 weeks ago. He REFUSES to go to the bathroom outside or on his pee pad! I’ve tried everything! Treats taking him outside every hour then I tried every 30 mins. He’s only done his business a handful of times. Every time I take him outside he just lays down. Nothing is working!!! I am out of ideas and don’t know what to do. I’ve only owned pits and naver had this issue! Please help!!!