My LED light is flashing 6 times. The panel indicates that this is a pressure switch fault. What do I do?

Replace the switch if you can find it. Those switches are difficult to locate if you have never done one before. They are most fequently mounted inside the furnace behind the blower door. Surface mounted abd look about the size of a quarter with two wires coming off it.

Some of those have an internal reset. Look for a little red button in the middle of a silver or black colored disc with 2 wires.