Hello we are looking at how we could implement automatic login in specific case.

Let's say we've got two subdomains: (a.abc.com and b.abc.com) which are subdomains of the domain: abc.com:

We use the okta sign in widget to login the user in a.abc.com. We are looking for a way to automatically login users in b.abc.com and vice versa if you are logged in b to automatically sign you in in a.abc.com. What would be the process to implement something like that ? Setting cookies with tokens and share it between both subdomains or there is other way ?