Do you have the manual?
HERE is a PDF that you can download. It covers the 2nd generation LMP.
Follow the guide in the manual to select a location (see below). If you have a Fiver or a TT, you should make sure that the location you have chosen will allow the LMP's signal to reliably reach the driver's position in your TV. You may need to experiment with each of the suggested positions until the signal is easily received on your phone/tablet. Use small Command strips to temporarily affix the LMP during this process.
Once you have found a suitable position, continue to follow the guide's instructions.
One important note: during the initial LMP setup process, make sure all your slides are out before you manually level your RV. Retract the slides and THEN set the LMP to level. Setting the "level" state this way accounts for any "side-lean" imparted by the slides' deployment.
HTH!