First, you need to determine if your router supports bridge mode.
In general, there will be options in the management interface of the router for bridge mode, wireless trunking, or WDS, etc.
If so, your router supports bridge mode.
If not, your router doesn't support bridge mode, and you may need to switch to a different router.
Then, you need to place the two routers you want to bridge in a position where they can receive signals from each other.
In general, the closer the distance, the better the signal and the better the bridging effect.
You can test the signal strength of both routers with your phone or computer to make sure they are both working properly.
Next, you'll need to set up your primary router, which is your parent router, which is the one that connects to the internet.
You'll need to log in to your main router's admin interface and find options for Bridge Mode, Wireless Trunk, or WDS, etc.
Enable it and record information such as the name, key, and channel of your primary router's wireless network.
You may need to set up a list of allowed bridging here, adding your MAC address from the router to it for added security.
Finally, you need to set up your slave router, which is your subordinate router, which is the router that connects to the main router.
You need to log in to your admin interface from the router and then find the options for Bridge Mode, Wireless Relay or WDS etc., and then enable it.
Enter information such as the name, password, and channel of the primary router's wireless network that you recorded earlier.
This allows you to connect your slave router to your main router for bridging. You also need to turn off your DHCP service from the router and let your primary router assign an IP address so that IP conflicts can be avoided.