It is a paid feature, different from the Flight Pass Premium.
You can buy it for a chosen duration, as there are different time options available. While it’s active, you will get additional bonus currency and experience points for different in-game activities.

Here are the benefits you get with an active Premium account:

– More currency (coins) from contracts during main game progression.
– No need to watch an ad to earn additional currency (coins) after completing a contract.
– More event points in Events.
– More currency (coins) for using the Worker (Pilots) feature.

You can purchase the Premium account for different durations. It does not renew automatically; therefore, after it expires, the benefits will no longer apply.