In Logic Pro, you must first click the Keyboard Split button to display the Remote (Key editor) button.
The type and number of available remote keys is determined by the Remote zone range. Keys outside this range are dimmed and assigned functions cannot be remote controlled with a MIDI keyboard.
Click the Remote button to open the Remote Key editor window.
A zoomed-in keyboard is displayed, with each key labeled according to its assigned function. Click the Remote button a second time to close the Remote Key editor window. You can also click the Keyboard Split button to exit the Remote Key editor window.
Drag the left or right border of the range bar above the Remote Key editor keyboard to resize the Remote zone.
Download the guides:
Logic Pro User Guide: PDF