I assume this is the crease from being on the bolt?  then the fabric is probably polyester and maybe difficult to remove.  Try using a 50/50 water and white vinegar solution on the crease.  Spray or dab it one and use you iron to dry it.  After removing the iron, while it's still good and warm place "clapper"  or somesuch device onto the crease area.  Let fabric completely cool before removing the device.

A clapper is a hardwood pressing aide but you can use a clean piece of hardwood like  a 2x4.  The wood draws the mositure and heat from the fabric to cool it and "SET" the shape.  I use this method to press poly seams open on a seam roll but the reverse should take out the crease.  If using a scrap piece of wood (must have some weight) I'd wrap it in thin muslin to be sure the satin is not stained.