redirection url

I’d like to ask you about one thing. How/where do you store redirection_url.
You’ve got this parameter in querystring. Then before redirect to (for example) Facebook you redirect to login.auth0… and set cookie. I suppose, you store redirection_url in session, because when I try to login from 2 different urls at the same time I’ve got an error for the last call. Am I right?
Tested on this examples.

At this time, initiating an authentication process, not completing it, initiating another, completing it and going back to the initial one will lead to issues. Trying to analyse the implementation details will also not improve this as it’s not something that you can influence. I can let you know that there are planned changes to how authentication transactions are handled which will likely result in an improved experience in this situation, however, at this time I don’t have any concrete information to share.

Thanks. I just thought where you store redirect_url and know I knew the answer