Are you using V3, aslo known as the "new chess.com" ? If so, then use the "Report a Bug" command from the Help menu (you can find it near the top of the screen, or in the lower left corner, depending on how you set your preferences).
If you're using old chess.com, use this link: https://www.chess.com/switch to switch to V3.
You can also submit a technical report via the https://support.chess.com/customer/portal/emails/new link, but the "Report a Bug" way is preferable (it will automatically capture the browser window content).
i am an ethical hacker, i have found few dew weakness in the login mechanism i would like to discuss them with the site admins or staff