NoDogSplash not showing up Automatically in client device

Hello guys ,I'm quite new to OpenWrt, and up to date, it's been smooth. I managed to configure the nodogsplash captive portal by following the docs and smart bloggers around. However, one thing is beating my logic. I configured a wireless access point and I'm able to connect to it with my phone but the nodogsplash cp. does not show up automatically that including manually going to the browser. If I type the router's IP address manually on the phone's browser it redirects to the same captive portal it couldn't show. My hardware is RPI B+. Any help is highly appreciated

Last year, the NoDogSplash project split, with NoDogSplash being stripped down to bare minimum for use on IoT devices with severely restricted resources.
openNDS is the new project, continuing with the full Forward Authentication Service API allowing full flexibility for customisation.

You might be better off opening an issue on github for this:

You might benefit from reading the full documentation here: