I was able to figure it out.
After loading the file by dragging and dropping the wireguard config file in LUCI GUI, Which of course came after installing the Luci app Wireguard In setting up the interface using the drag-and-drop method with the config file making minor changes such as allowed IP routing check
and going through the typical process of setting up what I usually do
this time I still set the allowed IP and route allowed IP's
set the persistent to 25
I changed two things in interfaces in the WAN interface I removed the VPNs DNS and replaced it with a regular one like Google Quad nine or even 1.1.1.1
but the biggest helper was changing the metrics. I gave The WAN metric with a better priority than the VPN( neither looks set by default) save changes
I turned off the VPN interface and restarted the router
note that I already had policy-based routing installed also known as PBR luci app
After rebooting, It's finally started defaulting to the WAN.
Restart the VPN interface a.k.a. turning it back on
now all that was left was to set the PBR As needed
A device that I didn't want using a installed client for (Windows or other operating systems) the router would be configured with the PBR such as letting it know to Pre-route all traffic to that specific VPN interface Based on IP address assigned and it has worked perfectly.(Though this means you would have to statically configure the IP address or if that's too cumbersome Due to DHCP you could use the Mac address instead)
Tip to make sure you understand which devices Belongs to which policy: name the policy based on the device In the VPN it's connected to As this will make it easier to turn off more
important note: On most VPN providers instructions the intention is to cover your entire network so they'll tell you to turn off or uncheck the box in the fire zone when it comes to forwarding traffic from the lan to the Internet.
if you want to split tunnel, you might not want to do that. you want to make sure to leave both the WAN & VPN available for the local area network To forward traffic to
The zone should show:
lan----> wan
vpn
not just:
lan----> vpn