The issue I am facing: When trying to access the admin page at http://192.168.8.103/admin an error will show that says: 403 forbidden and nginx/1.14.2.
Pi-hole uses lighttpd by default. Have you modded it, or is the address maybe not correct? Or are you using a reverse-proxy or a browser plugin that is interfering?
I haven't changed any setting on my raspberry or modded anything. I have the correct address. And I'm using basic google Chrome without any plugins or extensions.
Can you upload a debug log please? Run the command below in the Pi-hole terminal and select upload when prompted. Then copy and paste the token URL in here.