How to add buttons at interface Axis?

def goto_home(axis):
    if s.interp_state == linuxcnc.INTERP_IDLE:
        home = inifile.find('JOINT_' + str(inifile.find('TRAJ', 'COORDINATES').upper().index(axis)), 'HOME')
        mode = s.task_mode
        if s.task_mode != linuxcnc.MODE_MDI:
            c.mode(linuxcnc.MODE_MDI)
        c.mdi('G53 G0 ' + axis + home)

# make a button to home y axis
root_window.tk.call('button','.pane.top.tabs.fmanual.homey','-text','Home Y','-command','goto_home Y','-height','2')

# place the button
root_window.tk.call('grid','.pane.top.tabs.fmanual.homey','-column','1','-row','7','-columnspan','2','-padx','4','-sticky','w')

# any function called from tcl needs to be added to TclCommands
TclCommands.goto_home = goto_home
commands = TclCommands(root_window)

<hbox>
        <relief>RAISED</relief>
        <bd>5</bd>            
             <button>
                       <halpin>"zeropiece"</halpin>
                       <text>"Home Pieza"</text>
                       <font>('Fixed',11)</font>
                       <width>10</width>
             </button>
        </hbox>

        <hbox>
        <relief>RAISED</relief>
        <bd>5</bd>            
            <button>
                      <halpin>"touchplate"</halpin>
                      <text>"Sonda Probe"</text>
                      <font>('Fixed',11)</font>
                      <width>10</width>
            </button>
        </hbox>

MDI_COMMAND = O <zero_piece> CALL
MDI_COMMAND = O <touch_plate> CALL

net remote-zero_piece halui.mdi-command-03 => pyvcp.zeropiece
net remote-sondazero halui.mdi-command-04 <= pyvcp.sondazero

O <zero_piece> sub
G90
G0 Z5   (coordenada z que queremos)
G0 X0 Y0    (coordenada X Y Z de la pieza)
O <zero_piece> endsub
M2

O <touch_plate> sub
(*** GCode generated by NativeCAM for LinuxCNC ***)

(*.ngc files are best viewed with Syntax Highlighting)
(visit https://forum.linuxcnc.org/forum/20-g-code/30840-new-syntax-highlighting-for-gedit)
(or https://github.com/FernV/Gcode-highlight-for-Kate)

G21  (metric)
G17 G40 G49 G90 G92.1 G94 G54 G64 p0.001


#<center_drill_depth>       = -3.0

#<_pocket_expand_mode>      = 0

(optimization values)
#<_tool_eng1>               = 0.20
#<_tool_eng2>               = 0.30
#<_tool_eng3>               = 0.80

#<_feedfactor1>             = 1.60
#<_feedfactor2>             = 1.40
#<_feedfactor3>             = 1.25
#<_feedfactor4>             = 1.00
#<_feedfactor0>             = 1.00

#<_speedfactor1>            = 1.25
#<_speedfactor2>            = 1.25
#<_speedfactor3>            = 1.25
#<_speedfactor4>            = 1.00
#<_speedfactor0>            = 1.00

#<_probe_func>              = 38.4
#<_probe_feed>              = 200
#<_probe_latch>             = -1
#<_probe_latch_feed>        = 50
#<_probe_safe>              = 5.0
#<_probe_tip_dia>           = 3.0

#<_probe_tool_len_comp>     = 1
#<probe_height>             = 0
#<_tool_probe_z>            = 0.0

#<_off_rot_coord_system>    = 57

#<_mill_data_start>         = 70
#<in_polyline>              = 0

#<_has_z_axis>              = 1

#<_show_final_cuts>         = 1
#<_show_bottom_cut>         = 1

#<_spindle_all_time>        = 1

#<_spindle_speed_up_delay>  = 0.0

(end defaults)

#<_units_radius>            = 1  (for backward compatibility)
#<_units_width>             = 1  (for backward compatibility)
#<_units_cut_depth>         = 1  (for backward compatibility)

#<_tool_dynamic_dia>        = 0.0

(This is a built-in safety to help avoid gouging into your work piece)
/ o<safety_999> if [#<_show_final_cuts>]
/    o<safety_9999> repeat [1000]
/       M123
/       M0
/    o<safety_9999> endrepeat
/ o<safety_999> endif


(sub definitions)
(end sub definitions)


(begin Probe Surface)
(probe z and set author : Fernand Veilleux)

o<probe_surf_001_ena> if [1]
    o<probe> call [0] [0] [-1.000000]
    G10 L20 P#5220 Z[#<probe_height>]
    G0 Z[#<probe_height> + 55.000000]
    o<probe_surf_0010> if [1 EQ 1]
        M2
    o<probe_surf_0010> endif
o<probe_surf_001_ena> endif
(end Probe Surface)

O <thouch_plate> endsub
M2