Restylane to Fill the Crease on the Nose?

While traditional surgical rhinoplasty provides much wider options in terms of reshaping the nose, filling in a bifid tip such as you've shown, can be a simple in-office procedure.
For non-surgical rhinoplasty, I typically start with a temporary filler such as Juvederm so that the patient can see whether they like the effect without having committed to something permanent. If they enjoy that look, then a permanent filler such as Artefill can be used.
Using temporary fillers only requires returning to your doctor every few months to every year for the rest of your life. That gets expensive and tiresome for patients. Fillers and surgery both carry risks, too, so be sure to discuss that in detail with your doctor.
All the best,
--DCP

I have been performing nonsurgical rhinoplasties for well over a decade and I have found that treating a bifid nasal tip (a vertical cleft down the center of the nasal tip) with fillers yields consistently gratifying aesthetic improvement. I find that a combining a small amount of Radiesse with Perlane L works best for this purpose; the combination gives good lift and yields quite durable (long lasting) improvement. If, before treatment, you wish to get an idea of what the result might be, the cleft can be filled with a small amount of saline or anesthetic solution, both of which are reabsorbed completely in a few minutes after which the actual treatment can be performed. You should of course seek treatment by a board certified core physician with extensive experience with nonsurgical rhinosculpturing.

I think you're an excellent candidate for a Non-Surgical Rhinoplasty treatment. You appear to have very thin skin, and firm tip-cartilage so you can see the vertical crease in between your two lower-lateral cartilages. Your thin-skin / firm cartilage combination makes you a challenging Rhinoplasty Surgery candidate. I would strongly suggest keeping surgery as a last resort.
I know you don't want anything permanent, but I have had excellent success correcting this crease using Silikon-1000. All of my experience with Non-Surgical Rhinoplasty over the last 10 years has been with Silikon-1000, and I have no personal experience with temporary fillers in the nasal tip. The injection must be at the correct depth, so the experience of your physician is critical.
You should consult a facial plastic surgeon experienced with Non-Surgical Rhinoplasty, and you should see many photos before you proceed.
I hope you find this helpful.