Hi @Eimear.Doyle,
The custom-token-exchange-beta was closed to new participants in November 2024, but customers will be able to start onboarding once we open/announce EA, which is expected for the end of this month, January 2025. Therefore, you should be able to start using the Token Exchange feature around the end of this month.
Additionally, I recommend taking a look at this article: Setup SSO for Auth0 Sample App With Okta As IdP
Please let me know if you have any additional questions!
Best,
Mary Beth