i found a way to enable root password login to ssh
open router admin page
via LAN cable:
- browse 192.168.111.1:8000
- login with password 123456
- click wifi icon on top menu
- change the path at the end of the url (after random hash) with /admin/system/flashops
it will looks like this
http://192.168.111.1:8000/cgi-bin/luci/;stok=29698152cf64c980177a04f86c99ea0d/admin/system/flashops(the hash after "stok=" will be different) - restore the config with this modified backup
https://drive.google.com/file/d/1Vs-k7DHBSRZFfkxv1cMOmgAPZfB-RUen/view?usp=sharing - now you can login to ssh with root user and 123456 password, and backup all partition and upgrade firmware