In FL Studio, you can pull up a MIDI keyboard by first making sure that your MIDI keyboard is connected to your computer and recognized by the system. Then, in FL Studio, go to the "Options" menu and select "MIDI Settings." Ensure your MIDI keyboard is set as the input device in the MIDI settings. Then click on the channel rack and press the "+" button to add a new instrument channel, select "MIDI Out," and select your midi keyboard. After that, you should be able to play your MIDI keyboard and have the notes appear in FL Studio.