If you had a previous rhinoplasty, or any nasal surgery or trauma, the crease is most likely due to a broken cartilage/graft/implant. In such cases, the correct solution is to repair it surgically.
Non-surgical camouflage using fillers is a possible but tenuous option, as it can cause unsightly bulking up of the columella. In addition, it may be risky for skin necrosis as the columella skin is quite thin, and fairly high-pressure injection will probably be required.
Could it be a skin scar from a previous rhinoplasty? In that case, you can consider laser treatments, although it is usually inadequate for a surgical scar.
On the other hand, if you are perhaps referring to a crease forming at the junction between the columella and upper lip when you smile, it could be due to the way you smile. You could simply "re-learn" how to smile to avoid the crease appearing, or even consider some careful botox injection to the area.
Occasionally it could also be due to a misshapen anterior nasal spine, in which case surgery is probably your best bet.
