To make sure Wave works with Image-Line's FL Studio, navigate to the top left corner of your screen to FL Studio → Preferences → MIDI. Find Wave Bluetooth in the input device list and select Enable under the list.
In Softwave solo the function you want to map. Make sure your function has a dedicated CC number or Note (→ see Functions).
To map the function to a native plugin within FL Studio right click on the parameter you want to map and select "Link to Controller".
To map the function to a 3rd party plugin right clicking doesn't work. Instead move the parameter you want to map, for FL Studio to remember the last used parameter. Next go to Tools → Last tweaked and select "Link to Controller".
Depending on which of Wave's functions you are mapping, move, tap or click on Wave to make the link.
Now De-Solo the function in Softwave. The function should be mapped to FL Studio.