Why by default most of using openwrt on consumer cheap routers and ultimately we most of us if not all turn on wifi after install why not just turn that on by default and if don't want to do that just make prompt to set password and turn wifi on. So most don't have to worry about what is wrong and eliminate the unnecessary hassle.
Wifi is off by default for security. If a device is in its default state, the wifi credentials AND the router's admin credentials (via ssh and/or LuCI web interface) would be known and vulnerable to non-contact/proximity attack. This would be very bad. That is why wifi is disabled by default -- the user must enable it themselves, which also means usually they will set a password for both the router itself and wifi as well as change the SSID name.
This is not only good security practice in general, but also helps comply with laws such as this one.
I feel quite confident in stating that the OpenWrt devs will not enable wifi by default, ever.
It's quite well documented, so people shouldn't be surprised.
One of the reasons that people install OpenWrt is to improve the security of their router/network. So, the expectatoin is that they will also set a new password and SSID on their device anyway, so there isn't much "unnecessary hassle" when you consider that this is part of the expected setup process. However, if the user doesn't want to change the password and SSID, they can simply enable the wifi as an open wifi network with the default "OpenWrt" SSID (at their own risk, of course).
Thee are some situations where a user may need wifi enabled from the start (such as when a device is in a hard to reach location and/or ethernet connectivity to the lan is not available). Those users are the exception, not the rule, though, so the online image builder is perfect for that situation since they can customize the configuration that is 'baked into' the image. If that describes your situation, follow the link that @frollic provided.
Can i make a custom version inwhich i have all of my configuration baked in.
You've already been given all the information, which part of that is unclear to you?
Yes, you can.
How can i build it so i get the end result
And i want to do it here https://firmware-selector.openwrt.org/
What i need to add on the customize like where to put those script in whichway i don't understand how to do this.
that's exactly what the post I linked to describes ...
But i could not able to do it.
Then providing relevant details would probably beneficial to solving your problem.
- can you provide what you entered on the Firmware Selector
- can you explain in detail what you're not able to do (can you access the website, does it make an image, etc.)