First create new piece icons as Graphics expressions:
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iconGraphics=Graphics@Text@Style[#,FontFamily->"Chess Alpha",FontSize->34]&/@{"k","q","b","r","h","p","l","w","n","t","j","o"};
Assign each icon to different piece type in an Association (“K” stands for white king, “k” - black king, “Q” - white queen, “q” - black queen, etc):
In[]:=
icons=AssociationThread[{"K","Q","B","R","N","P","k","q","b","r","n","p"},iconGraphics];
Import chess position as graphics with custom icons:
In[]:=
ImportString["5n2/3nrpk1/1qBp2p1/p2P3p/1rp1PP2/2N4P/1P2RQP1/4R2K w - - 4 69","FEN","Icons"->icons]
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