How to sync my account with Trakt.tv?
To link your Trakt.tv account to your BetaSeries account, go to My account, "External services" section of the left-hand menu, then click "Trakt.tv". Enter your Trakt.tv username there (careful, it is not your email address).

One of the main advantages of this sync is that Trakt.tv in turn allows the integration of many plugins and applications. This way, you can use these plugins to automatically update your BetaSeries account. Once your accounts are linked, the BetaSeries bots will look for the episodes and movies watched on Trakt in order to update your BetaSeries account. To also add the shows from your Trakt account, tick the option "Allow the automatic addition of shows added on my Trakt account".
If you add an episode to your collection on Trakt.tv, it will also automatically be marked as "collected" on BetaSeries, provided you have ticked the option "Add an option in "My episodes" to mark episodes as "collected"" in your account setup ("Options" section).

Finally, if your Trakt account is private, you will also need to add the "BetaSeries" account as a friend on Trakt.tv. Once the friend request is accepted, the sync will begin.