Unable to log-in

Took a break from game since 2020. Now idea what and when was changed. Now can't login entirely. When I played game I had both password and security key on my account (original, not google ID).  Have display name and password stored. Lost security key. From what posts here say, you can login leaving security key blank to trigger one-time password recovery.

How it looks to me: With display name and password filled, game gives a "Login failed due to invalid captcha". No captcha ever shows up.  Tried Firefox 147.0.4 (64-bit) (with all extensions disabled and separately in private mode) and Microsoft Edge (up-to-date). Same errors, keeping up for 3+ hours. Cleaning browser cash and cookies did not help.

Additionally tried "I don't remember my display name." which confirmed I was using the right one. 

So? How to get into my account?