the raw fractal.lua is too small to see,and it can't display number 3 ,so i looked up the ebook ,modified it to this one.
up1 = instance:createTextOutput ("", "UpL", "calibrib", 18, core.H_Right, core.V_Top, instance.parameters.clrPrice, 0);
down1 = instance:createTextOutput ("", "DnL", "calibrib", 18, core.H_Right, core.V_Bottom, instance.parameters.clrPrice, 0);
font "calibrib" solved the mistake ,
fontsize 18 is better