I can confirm that this is correct, as all custom apps are no longer created via the Store’s Admin, and instead created and managed via the Dev Dashboard.
The access tokens are no longer available via the Admin or Dashboard diirectly, and you will need to use one of the existing authentication methods in order to receive the access token.
@Issa_Alsheikh_Hasan is correct in that this is one of the authentication methods you can use to generate an access token for a custom app, specifically they are describing the Authorization Code Grant method.
This way is a little bit more complex, and for custom apps specifically we do recommend using the client credentials grant method instead, as it’s much simpler, and I’ve described this further in the following existing forum thread: