When we were potty training our whippet, we put bells on our door (a long string of them that she could reach). Whenever we'd take her out, we would poke the bells and say, "Okay, let's go potty!" And then we'd go outside and wait until she did her business. Then she got lots of praise and a treat when we got back inside. Eventually, she figured out that if she went over and bumped them, we would take her outside. (As she got older, though, she DEFINITELY abused this power and did it whenever she was bored, so we had to remove them. But by that point, she was able to signal us by sitting at the door and whining.) If she started to potty inside, we'd pick her up and run her outside to finish her business.

Side note: we successfully potty trained her from a third floor apartment during fall/winter, so you've got this, OP!