Error 5005 - Digital Input channel not available for Arduino Mega + Ramps 1.4

[avrma]

Hey everyone, so I've been trying to run a servo motor through ramps 1.4 and arduino Mega and I'm getting error 5005.

This would make sense if I weren't using the ramps board which according to the website (https://reprap.org/wiki/RAMPS_1.4)  allows pin 54.

Can anyone tell me how I could resolve this problem?