Display INPUT txt in DYNAMIC txt boxes

I have a INPUT TEXT inside a mc called “txt mc” and DYNAMIC TEXT in the main time line.
I’m trying to display what’s typed in the INPUT TEXT (my_Input_Txt) in the DYNAMIC TEXT boxes (my_Dyn_Txt1, my_Dyn_Txt2, my_Dyn_Txt3)

Here’s the code. But it won’t simply work perhaps because the INPUT TEXT is inside a MC. I need to have the INPUT TEXT INSIDE THAT MC while having the DYNAMIC TEXT boxes out in the main time line. How to fix this? What am I missing?

my_Input_Txt.onChanged = function() {
my_Dyn_Txt1.text = my_Input_Txt.text;
my_Dyn_Txt2.text = my_Input_Txt.text;
my_Dyn_Txt3.text = my_Input_Txt.text;