Wifi extender / router, wlan1 -> wlan0

Hello,

I am trying to build the wifi extender for my next holiday, because usually the hotels wifis has poor signal to the rooms.

I have old oneplus phone with kali nethunter installed, and i have working external wifi with OTG usb. I am able to create working router with private wireless network with external adapter (wlan1) to the external network with internal adapter (wlan0). I have create my own scripts, and i also found mana scripts, which seems to do same ( simple ).
But, what i need, is to configure external adapter ( wlan1 ) to connect to internet, and the internal adapter ( wlan0 ) should be work as access point to private network, because external adapter has stronger signal and external antenna.

I am able to start the interfaces fully, and hostap, wpa_supplicants are start, and ip is assigned, and my client is connecting wlan0, and even dns requests are working, but the client is not able to connect to the internet. Even oneplus shows that it is offline mode..There is some ip rule table definition in mana script. ip rule is not familiar for me..

Any hints how to proceed?

Use the hotspot feature on your Android.

If using just linux stuff, look up linux routing, ip forwarding, masquerade and iptables.

it looks like you miss "bridging" correctly the interfaces
In order to be able to tell you something we would need to see your conf' files and the command lines you used.
It is worst mentioning the excellent create_ap (much better than any kind of android feature)