Issues with sensor

Hello how I replace a door sensor. I bought a new one but it is not linking.

It looks like you were already able to resolve this, but for anyone else, first you will want to ensure that the old sensor has been removed from panel programming.

Then, you will want to program in the new sensor. Both of these actions would be done directly from the panel.

You can find sensor pairing instructions for a variety of panels on the How To page of the forum.