You will find a very simple example in the file graphics\checkbox.asm.
;---------------------
Includes ---------------------
include
"tios.h"
include
"api92.h"
include
"api92cst.h"
;------------ Start of assembly program -------------
xdef
_main
xdef
_comment
_main: moveq.w
#1,d0
jsr
api92::SetFont
lea
cb_1(PC),a0
jsr
api92::CheckBoxComponent
jsr
api92::WaitKey
rts
;-------------------
Program Data -------------------
cb_1: dc.b
1,0,10,20,"Style 1",0
_comment dc.b
"CheckBoxes Examples",0
;--------------------
End of program ------------------
end