ID:2286973
 
(See the best response by GreatPirateEra.)
https://gyazo.com/559a370c2d690aba6e6d7289580a1461

Any way to bypass that? I want to roll my own account/login system. I don't want them to have to make a BYOND account.

If it is not possible, BYOND should look in to making it possible. For the webplayer it is objectively not a good idea to force them to make accounts. I don't want that screen to even appear.
I don't want them to even see that screen. I want them just load in as a guest and I'll handle it from there. Give BYOND the option to skip that screen. Thanks.
There's probably a way to default force join as a guest ignoring the account they're logged into, and then open up a custom login system afterwards. As for how to go about that ...
Best response
This has been suggested ever since the webclient's inception.