What the heck is xy in the xyPPS?
whatever it needs to be
eg on your chip

if its an input then xy= the input to the module
ie.
RXPPS = 0x09; //RB1->EUSART:RX;
makes rx on portb.1

if its an output then xy= the output port/pin for the module
ie.
RB0PPS = 0x24; //RB0->EUSART:TX;
makes tx on portb.0