timer doesn't work when 'autostart' option is off

Question

https://youtu.be/3Fvt0k7lnc0?t=398
This is the tutorial I've been following.
In the tutorial 'autostart' in timer node is off and enemies are spawned without any problem.

I wrote the exact same code except for a few variable names.
However, in my projects, when 'autostart' is off, enemies do not appear at all.
I found out when I turn on the 'autostart', enemies are spawned just like the tutorial.
I don't understand why the code works differently when I'm using the same code.
I want to know how can I make it work with 'autostart' turned off.
Because I want first enemy to appear after 3 seconds, not right away.
This is my code. >> https://pastebin.com/rA1T0Kbr

Thank you in advance. :))

Answer 1

If you want a timer to work you need to start it , autostart starts the timer by default so its same as
func ready ():
$timer.start()

Answer 2

note the following :

this is user defined function : ready()
this is already defined virtual function : _ready()