How to configure 2 isp connections (wan + bridge)

Hi, I have on my openwrt router (old wr1043nd) 2 connections, 1 ppoe connected to wan port, which I plan to use as backup, and the other fiber connection with its own modem. I use openwrt only as a bridge to fiber isp. I have static IP on openwrt with static gateway to fiber modem (configured on lan interface), vdsl ppoe has its own public IPv4. When I use option defaultroute '0' on pppoe, router is not reachable from pppoe IP. Can I use somehow both ipv4 connections? I'd like to make openwrt reachable on both IPv4 adresses (fiber+vdsl)? How to do that? Thank you for hints.

Use mwan3 package

Thank you, I will try it. The trouble is the fibre modem is in the same lan subnet as my openwrt router and fibre modem is doing nat itself also forwards ports to different IPs inside lan. Do I need to readress it and make dual nat or mwan3 can make 1st wan bridge and 2nd wan pppoe?