Archer C7 bad config

I tried my Archer C7 in bridge mode, but it did not work, now the router boot up, but I do not have access to it anymore, I do not have an ipv4 address on the LAN port, an IPv6 address appears to be on the router, but when I type in browser does not open the LUCI.

how can I do to reset the modem? I tried the reset button but I was not lucky.

thanks any help

Try failsafe mode

then do a factory reset

https://openwrt.org/docs/guide-user/troubleshooting/failsafe_and_factory_reset