Filler cycle duration after treatment

Hello, I am an office worker considering filler treatment because my nasolabial folds have gotten too deep lately.
Since this is my first time getting it, I have a lot of questions. How often should I schedule fillers for maintenance?
I want to try it once before deciding, but people around me say that to get a nice shape, I need to shorten the filler interval and get a touch-up one more time.

I am also curious if the filler injection cycle varies significantly depending on whether the product is domestic or imported. I have heard that getting injections too frequently can cause the filler to spread sideways or form layers, so I would like to know the appropriate injection interval to safely maintain volume.