Answer
Thank you for the message. Yes; the PSR-E333 is designed to work with the FC5A pedal. Using it with the PSR-E333 gives you foot control over whether the notes are sustained (as you'd have when playing an acoustic or digital piano).
You can also switch the sustain effect on using Function 022 from the keyboard's own controls but this isn't feasible or practical whilst playing the keyboard with two hands.