rznc-0501 4th (c) lathe axis

hi, i have this control board running(picture attached), i tried to wire another stepper to c axis and give it some gcode with 4th axis generated with rhinocam.

now the new stepper not act like a 4th axis but move together with y axis, so i assume they made that slot for machines which need double y axis motors. but thinking maybe it's from firmware or maybe it's gcode.

so wanted to ask, if i upgrade firmware is it possible to use that c axis as 4th axis?

if not, a 3 axis lathe still will be useful for me, what is the best way to use x, z and lathe axis and easily switch back to x, y, z axis?

gcode is here also if you think it's faulty, it's just for simple cylinder:

O 1000;
N1 G00 G17 G40 G49 G80 G90 G98;
(4th Axis Parallel Finishing)
N2 G21 T1 M06;
N3 G90 G00 X0. Y0. S0 M03;
N4 G43 Z13.071 H1;
N5A0.F10.000005
N6G01Z5.A0.F1125.
N7X20.A0.F1000.
N8Z4.997A-8.6F1000.
N9Z4.985A-17.1F1000.
N10X0.A-17.1F1000.
N11Z5.A-21.4F1000.
N12Z4.987A-25.7F1000.
N13Z4.999A-34.3F1000.
N14X20.A-34.3F1000.
N15Z4.996A-42.8F1000.
N16Z4.978A-51.4F1000.
N17X0.A-51.4F1000.
N18Z4.999A-57.9F1000.
N19Z5.A-68.6F1000.
N20X20.A-68.6F1000.
N21A-79.3F1000.
N22Z4.986A-85.7F1000.
N23X0.A-85.7F1000.
N24Z5.A-90.F1000.
N25Z4.986A-94.3F1000.
N26Z4.996A-102.9F1000.
N27X20.A-102.9F1000.
N28Z5.A-111.4F1000.
N29Z4.992A-120.F1000.
N30X0.A-120.F1000.
N31Z4.999A-124.3F1000.
N32Z4.997A-137.1F1000.
N33X20.A-137.1F1000.
N34Z4.999A-145.7F1000.
N35Z4.987A-154.3F1000.
N36X0.A-154.3F1000.
N37Z5.A-158.6F1000.
N38Z4.996A-167.2F1000.
N39Z4.997A-171.4F1000.
N40X20.A-171.4F1000.
N41Z5.A-180.F1000.
N42Z4.997A-188.6F1000.
N43X0.A-188.6F1000.
N44Z4.986A-194.7F1000.
N45Z4.987A-205.7F1000.
N46X20.A-205.7F1000.
N47Z4.999A-212.1F1000.
N48Z4.997A-222.9F1000.
N49X0.A-222.9F1000.
N50Z4.988A-229.F1000.
N51Z5.A-237.6F1000.
N52Z4.992A-240.F1000.
N53X20.A-240.F1000.
N54Z4.999A-249.4F1000.
N55Z4.996A-257.1F1000.
N56X0.A-257.1F1000.
N57Z4.989A-263.3F1000.
N58Z4.999A-271.4F1000.
N59Z4.986A-274.3F1000.
N60X20.A-274.3F1000.
N61Z4.999A-281.7F1000.
N62Z5.A-291.4F1000.
N63X0.A-291.4F1000.
N64Z4.992A-300.F1000.
N65Z4.978A-308.6F1000.
N66X20.A-308.6F1000.
N67Z5.A-315.F1000.
N68Z4.999A-325.7F1000.
N69X0.A-325.7F1000.
N70Z4.981A-331.8F1000.
N71Z4.987A-334.3F1000.
N72Z4.985A-342.9F1000.
N73X20.A-342.9F1000.
N74Z4.999A-350.4F1000.
N75Z5.A-360.F1000.
N76X0.A-360.F1000.
N77Z13.071A-360.F1875.
N78 M02;