Ok, this is a little confusing-ish but I'll try. Your transmitter is at top left -p the microphone plugs into it with it's 2 contact plug. Nothing to be done there.
You want to run the receiver into your phone. From the device at top RIGHT. You obviously have the wrong plug sticking out of it as that has 3 contacts - tip, ring(base) and sleeve(the small one in the middle - that is stereo. The signal; chain would never end that way - the microphone starts as mono, it will leave the receiver as mono(a mono, j/k).
You need the same plug you show at top right circled in MONO. Just tip and sleeve. Your phone's mic is also mono and if you have a mic jack it is mono, not stereo.YMMV