what is spell Fields

in the spell chess variant fen there is spellFields what is it

Blu spell freezes a 3x3 tile of the board You nan evade checks by freezing the checking piece Green lets You move through a piece as If it never existed

i know how to play but in the fen there is spell fields what is it?

Wdym spell fields

R-0,1,0,1-1,1,1,1-1,1,1,1-0,0,0,0-0-{'pawnBaseRank':5,'wb':true,'dim':'8x8','spells': ()'jump_0x2,freeze_0x5','','jump_0x2,freeze_0x5',''),'spellFields': ())}-
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,yR,yN,yB,yQ,yK,yB,yN,yR,x,x,x/
x,x,x,yP,yP,yP,yP,yP,yP,yP,yP,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,8,x,x,x/
x,x,x,rP,rP,rP,rP,rP,rP,rP,rP,x,x,x/
x,x,x,rR,rN,rB,rQ,rK,rB,rN,rR,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x/
x,x,x,x,x,x,x,x,x,x,x,x,x,x

this is the FEN

Ask somewhere like general discussions or google it

You might get help there

googled found nothing