First find out what still works.
A missing remote, an awkward phone app, and a treadmill that will not respond are three different problems. These guides help you choose the right next step.
Paceora can replace a daily controller. It cannot repair a treadmill.
If the hardware powers on and responds somewhere, Mac control may help. If no controller can reach it, start with WalkingPad hardware support.
WalkingPad hardware support