Found this in KVR to change tempo in FL:
"Check the Image Line forums, plenty of posts on this topic. One simple way to switch between two tempos:
1) Right click on the tempo (i.e. 110 bpm), select create automation clip.
2) Set tempo to the first tempo (slower one, for example 110 bpm). Right click tempo again, select copy value. Then select the automation clip channel, right click "min", select paste value.
3) set tempo to the second tempo (faster one, for example 120 bpm), right click it, select copy value. Select the automation clip channel, right click "max", select paste value
You can now shape the automation clip to switch between the "min" (110)and "max" (120) values or anywhere in between."
The FL metronome should track the tempo automation click.