^ Yep. OP already had it connected to the air box.
He just needs to be careful where the tube is placed if he continues to use one. One must ensure it’s not placed in a strong air stream since this can result in ventrui effect which can gives rise to false air pressure signal to the converter. (At school we created vacuum by connecting 2 joined tubes to running water so the concept shouldn’t be foreign to anyone who did high school chemistry.) Meanwhile the length of the tube can also have an impact in how long it takes to get the pressure wave to the converter. All this means it can be difficult to tune on LPG system, especially the throttle transient response which is why some installs simply have the converter port disconnected and protected from wind. (If one has issues using a tube to the air box, simply zip tie some air cleaner foam around the protected open port of the converter as it’s much easier).
Probably what should be said is that in all states you need to be a licensed LPG mechanic to install and service LPG systems
Running around with an uncertified install can land you in big trouble