In this video, I have shown how I Extended my Home Fiber Internet to my other room using an old DSL router.
I have used my old Huawei router and converted it into WiFi Repeater, WiFi Extender, WiFi Access Point, and network Switch.
I have extended a 20 Meter long ethernet LAN cable from my New router and extended it to the LAN port of the Old Huawei router Model number: HG630a
First I reset it and then turned off the DHCP service and changed the default gateway to another IP from the default 192.168.1.1 address.
You might be having an old router in your home, but now you can use it as a WiFi extender to extend your WiFi network coverage in your entire house.

Links:
LAN Cable https://amzn.to/42AIKpH
Fiber Router New https://amzn.to/3ZiEpEs

Head Phone and Mic https://amzn.to/40DQN2X
4G Router https://amzn.to/3TMlIrR