Extract Chromium passwords stored via Kwallet

So I have Chromium (137), and Kwallet, and they work ok, Chromium saves and offers passwords on sites, and they are correct. But I want to backup my passwords to external drive (and there are another use cases when I need plain-text password, like console github login), so I opened Chromium password manager - and it was empty. No passwords at all. Offering passwords on login screen still works OK. Do you know how I can extract passwords from 'Login Data' sqlite using Kwallet key (I tried kwalletcli -f "Chromium Keys" -e "Chromium Safe Storage" and it returned me something looks like a key) or just make Chromium password manager work? Thanks