no audio on toyota highlander 2018 with jbl

hi there i just installed the headunite , i do have steering wheel fonction rear back view camera but no voice what so ever so we installed a aditional modul to try to get sound and it worked , so this is the moduel part number that ive tested to get audio out : RP4.2-TY11
So can someout help me trouble shoot the problem thx u all