My metal jumper wire fell out of my new thermostat, which terminals does the jumper need to be connected to on the thermostat wallplate?

The jumper wire can easily be replaced connecting it to the "R" and "RC" terminals on your thermostat wallplate. If you are unable to find the factory installed jumper, a short piece of wire can be used in its place. Please refer to step 1.7 in the Quick Start Guide.