Do you mean you want to rotate the ship?
Here is how you get movement angle:
angle(0,0, Ship.Physics.VelocityX, Ship.Physics.VelocityY)
You can slowly change ship angle until it reaches this angle, for example:
Ship -> Set angle to anglelerp(self.Angle, angle(0,0, Self.Physics.VelocityX, Self.Physics.VelocityY), dt/2)
It's not recommended to change angle for physics objects directly, so you can try to do the same with physics actions like "set angular velocity".
And, of course you should only adjust the angle when player is not controlling the ship.