No, Dropbox no longer offers the option for retrieving new long-lived ("no expiration") access tokens. You can find more information on this migration here. Instead, to get long-term access, apps should request "offline" access, in which case the app receives a "refresh token" that can be used to retrieve new short-lived access tokens as needed, without further manual user intervention. You can find more information in the OAuth Guide and authorization documentation.
For reference, while the creation of new long-lived access tokens is now deprecated, we don't currently have a plan to disable existing long-lived access tokens. (If that changes, we will of course announce that ahead of time.) That being the case, you can continue using existing long-lived access token(s) without interruption, if you have any.
