Deleted 206 days ago
My suggestion is to first look for your hero id. It's a number that appears in the bottom left of the screen with authenticating your account on log in.
To find it: Open the game in the browser, look for the icon that says 'Hero' in the bottom left. It'll show your profile page - chosen hand, health, base damage, name, etc. Next to your name is an 8 digit number inside brackets eg (67891234). That is unique to your account.
Next, email: support.app@flushee.games. They are the publisher/developer accredited on steam for dealing with Dirty League. I have emailed them before regarding glitches during events. Explain your situation and what you want to do. For the record, they are based in Cyprus so GMT+3 for time zone, as it's summer time.
They might be able to provide you with a copy of the relevant .dll file, that you would need to overwrite to change your steam id to match your browser id. You'd have to place it somewhere in: C:\Program Files (x86)\Steam\steamapps\common\DirtyLeague, probably \DirtyLeague_Data\Managed. My best guess is that the file is named ''Sentry.System.Collections.Immutable.dll''
I'm not familiar with the .dll file types used by unity, so I don't know which file reader you'd need to go in and manually change your hero id, if you wanted to do it yourself. It's not something they'd openly disclose to prevent account hijacking.